This appear to be highly unlikely for several reasons:
The Black Sea is currently ice-free. If any NATO actions (NATO being a military and not a political organization) were to take place they could easily occur now as there little to prevent sea or land resupply of any military.
If the questioner means the European Union, a political body, instead of NATO, then this again seems unlikely as factories and homes would still require natural gas supplies for water heating and production There is no "ideal time" for the combined nations of Europe to take unified against the only thing that would hurt the Russian economy in the short-term: reducing or ending imports of natural gas.
By waiting instead of acting now, both the EU and NATO risk Russian troops consolidating the positions making any peaceful efforts to remove them extremely difficult or making the installation of an armed peacekeeping force, impossible.
If the EU or NATO (or both) are going to take any action against Russia for its invasion of the Crimean Peninsula, waiting offers far greater risks than immediate action.