it's fine. your attorney should be able to handle this situation easily, usually, there is certain ammount of deposit holding by your attorney to protect you.
My seller asked for staying longer after closing, we actually didn't want to move that early, so they paid rent by days and the rent would go up greatly after the date they promised to move out. My seller are pretty nice people, they cleaned and decorated the house before we moved in, they even put brand new paper roles in each bath room. My friend lives nearby actually permitted their seller stayed about 1 month free for part of the price bargain as they preferred move in a month later while the seller didn't have to get a temporary place for his next place . but,again, it all depends on what kind of seller you are dealing with, it may turn out to be a nightmare.
