i definitely know what you're saying about time limitations in general, i do have 24 hour days and no money tree either.
regrettably.
i'd be content with 30h and a small change bush already
...and i DO understand (and share) the pressure of the 1st playthrough, because. you. just. want. to. know. now.
but _none_ of this, not even the latter, will make it _impossible_ for you to play.
it may make it impossible to play _the_way_you're_used_to_.
but who says you can't take three years to complete your first playthrough? it's _your_ game!
as you correctly assumed, my own playstyle is pretty much like this already anyway, and on low levels, it can take me 1-2 days (= time i can play in a real day) to clear out a bigger dungeon location or get from goodneighbour to dc in one piece - so what? if i hadn't met father before 2018, who'd mind?
and one thing i can assure you of: it's challenge. not one second of this is boring. (quite the opposite, i personally find it boring as hell to clunk in in power armor and minigun whatever moves, yaaaaaawn....)
but admitted you'll likely not exactly get to do getting-things-done-runs.
but even then: like my char is now, lvl 83 and expert in pretty much everything, i just wouldn't mind, cuz i don't die, it's a tuxedo law
really, i think you just need to drop the idea of a game being something to be consumed in favor of it being something to grant you an experience and you'll be fine.
even if you'd never even finish the mainquest or whatever.
...and a reminder to put all this pretty much into relation: you still can change difficulty back anytime anyway