Room Blocking for Mansion Wedding (?)

Good evening WW crew! So I am debating between a hotel beach front venue and a Mansion venue. I understand how room blocks work for a hotel venue, but how does it work if you aren't getting married at one? Can you still request room blocks at a nearby hotel? Is it a free for all and all guests just find their own accommodations? Just about everyone attending/ part of this ceremony will be from out of state (self inlcuded). I appreciate any and all feedback...