Apparently personal bunkers weren't popular even during the Cold War.
https://vc.ru/story/139377-mesto-gde-mozhno-spryatatsya-skol...
It may be that people just didn't have the money for this kind of stuff and oligarchs would rather build castles that no one knows about than buy old bunkers (which would be in way worse shape in ex USSR I imagine).
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.
You'll still just be a resource cache for whatever roaming bands of anarchic clans that develop amidst the fallout. And subsistence farming is a complete fantasy; you'll starve very quickly. The only survival scenario that is realistic in an apocalyptic world is one built around trade, alliances, and firepower. Feudalism, essentially. Anyone who thinks they'll be able to go their own way and remain hidden will be the first ones killed off.
Which sounds good until you need a dentist or doctor and you discover you forgot to bring a surgery and/or hospital.
Or a vet. Or spare parts. Or tools/medications you don't already have.
Or any essential consumable that has a shelf life of (if you're lucky...) less than fifty years.
https://www.smithsonianmag.com/history/for-40-years-this-rus...
E.g. live far away from miltary installations, keep a reasonable distance from metros, and avoid any place between the Appalachian mountains and the Sierra Nevada mountains (due to fallout).