You wrote, "the vote in the House is 'by states'". That is incorrect. AMENDMENT XII , referring to electoral votes, "The person having the greatest Number of votes for President, shall be the President, if such number be a majority of the whole number of Electors appointed". Barring some strange occurrence, Biden will have a majority of electoral votes. There will be no vote in the House "by states".
Is this still a danger, technically?
No.
[The following text was divided into paragraphs, otherwise it would be "wall of words". The first part (removed) deals with the opening and counting of votes. The third part (removed) deals with multiple slates.]
3 U.S. Code § 15 - Counting electoral votes in Congress
[...]
Upon such reading of any such certificate or paper, the President of the Senate shall call for objections, if any. Every objection shall be made in writing, and shall state clearly and concisely, and without argument, the ground thereof, and shall be signed by at least one Senator and one Member of the House of Representatives before the same shall be received. When all objections so made to any vote or paper from a State shall have been received and read, the Senate shall thereupon withdraw, and such objections shall be submitted to the Senate for its decision; and the Speaker of the House of Representatives shall, in like manner, submit such objections to the House of Representatives for its decision; and no electoral vote or votes from any State which shall have been regularly given by electors whose appointment has been lawfully certified to according to section 6 of this title from which but one return has been received shall be rejected, but the two Houses concurrently may reject the vote or votes when they agree that such vote or votes have not been so regularly given by electors whose appointment has been so certified. [Emboldening added]
[...]
When the two Houses have voted, they shall immediately again meet, and the presiding officer shall then announce the decision of the questions submitted. No votes or papers from any other State shall be acted upon until the objections previously made to the votes or papers from any State shall have been finally disposed of.
In the emboldened part, note that no "lawfully certified" votes "shall be rejected", if the governor of the state follows the requirements under 3 U.S. Code § 6. However, both the House and Senate must agree in order to reject votes not certified. which is not likely to occur in this election. Note that there is nothing in the law permitting the House to reject electoral votes "by state" and that rejecting the votes of any state requires that both the House and Senate must agree.
On January 6, 1969, during the counting of electoral votes, an objection was raised to the votes of North Carolina. The vote was twelve for Richard M. Nixon and one for George C. Wallace. The objection was raised and signed by James G. O'Hara, M.C. and Edmund S. Muskie, U.S.S., with additional Representatives and Senators joining the objection. The objection was due to a so-called "faithless elector".
We object to the votes from the State of North Carolina for George C. Wallace for President and for Curtis E. LeMay for Vice President on the ground that they were not regularly given in that the plurality of votes of the people of North Carolina were cast for Richard M. Nixon for President and for Spiro T. Agnew for Vice President and the State thereby appointed thirteen electors to vote for Richard M. Nixon for President and for Spiro T. Agnew for Vice President and appointed no electors to vote for any other persons. Therefore, no electoral vote of North Carolina. should be counted for George C. Wallace for President or for Curtis E. LeMay for Vice President.
The Senate retired to their chamber to consider the objection. The House began its consideration after the Senators left. This discussion lasted for nearly three hours.
Among the issues was whether "regularly given" applied to faithless electors.
During the consideration in the House, it was stated that the Governor had certified the vote and that North Carolina had no law prohibiting the vote for Wallace.
After the Senate returned to the House, the votes were given. The Senate voted against sustaining the objection 33 to 58, the House against 170 to 238. The vote for Wallace was allowed.
The remaining electoral votes were counted.
The PRESIDENT pro tempore. The state of the vote for President of the United States, as delivered to the President of the Senate, is as follows:
The whole number of the electors appointed to vote for President of the United States is 538, of which a majority is 270.
Richard M. Nixon, of the State of New York, has received for President of the United States 301 votes;
Hubert H. Humphrey, of the State of Minnesota, has received 191 votes.
George C. Wallace, of the State of Alabama, has received 46 votes.
The state of the vote for Vice President of the United States, as delivered to the President of the Senate, is as follows:
The whole number of the electors appointed to vote for Vice President of the United States is 538, of which a majority is 270.
Spiro T. Agnew, of the State of Maryland, has received for Vice President of the United States 301 votes.
Edmund S. Muskie, of the State of Maine, has received 191 votes.
Curtis Lemay, of the State of California, has received 46 votes.
This announcement of the state of the vote by the President of the Senate shall be deemed a sufficient declaration of the persons elected President and Vice President of the United States, each for the term beginning on the 20th day of January, 1969, and shall be entered, together with a list of the votes, on the Journals of the Senate and House of Representatives.
The joint session ended with no further action.
The House Manual shows this as the only case where an objection was acted on under the current law, which was enacted in 1948.