canada
What would such a question do without some Canadian Anglo/French drama, n'est-ce pas?
In Canada, the system is defined to have 2 official languages, French and English. Let's leave aside some of the, rather peevish, limitations Quebec is always trying to put on the English language and concentrate on what is agreed upon federally.
You can access legal systems in your language of choice. Certainly Federal courts, and theoretically at least Provincial Courts.
You can be schooled in one of the two languages you desire, provided you qualify for it. Theoretically, that means if either of your parents were schooled in English you ought to be able to get schooling in English in Quebec. Or vice versa, outside of Quebec. My kids were schooled in French in Vancouver, which doesn't have that many French people in it.
Dealing with the federal bureaucracy is also available in your language of choice. For example, tired from a flight, I said "bonjour" to the Canadian border services person at Vancouver airport on arrival. Not a word was said, I got escorted to another line, where the officer could speak French (no, I didn't jump any queues as a result).
This is less linked to local population proportions than it is to an individual having demonstrable links to either of the 2 official Canadian languages. In practice, this may be less true in less populous areas. I can't see some of the smaller British Columbia towns offering much of a French school experience, due to limited demand. The same might be said of expecting English services in the Quebec back country. But that's at least the theory.
The all-country stats are roughly 20% Francophones vs 75% Anglophones, but that varies widely by region, yet the principle of access is, again theoretically, nation-wide at the Federal level. At the Provincial government level, bilingualism is perhaps more aspirational in many regions (I doubt I'd get far trying to speak French in BC and I know English-onlies who struggle mightily dealing with the Quebec government).