Bunkers aren’t that great for long term survival. You’re effectively betting that you can survive in a small isolated prison for N years to emerge without resources or the ability to feed yourself. You are also betting that the underground structure isn’t going to need maintenance in those N years, and that you won’t simply be viewed as a resource cache by whoever is still on the surface.

Now if we start talking about remote bunkers far away from cities - you start also asking the question of why you would need a bunker! If you build an off grid house in Whistler BC you are highly unlikely to be targeted by a nuke, or be in the fallout zone of any nukes. Rural east coast and southeastern US are also great options. You can even set up a plan for a permanent farming installation in the event of a disaster.