Are you just looking for somewhere to stay for one night on the way down? You may actually have a bit of a problem finding somewhere... most places are resorts rather than hotels, and most seem to insist on a minimum of two or three nights. We found this out earlier this year when we had to break our journey into shorter chunks because one of us (me!) was cycling. Unless there is a pressing reason to stay in Key Largo I would say that Homestead is your best bet.