The home sale contingency is strongest when your buyer's home is already under contract and you make all other terms attractive.  

Another thing to think about is what alternatives do you have other than a conventional 20% down owner occupied loan or a 3.5% FHA loan.

Alternately, I could just get a newly developed house and pay full price = market value and not have to deal with a house in this competitive environment.

With all of my alternative suggestions, I will leave you with 1 caveat.

@Michael Carges that’s a great area and attracting a lot of the new transplants.

More expensive rental homes in Vegas can attract a high rent rate but also a more transient renter (stay for a 12-18 months or less) who can afford to eventually buy their own home.

Maybe with remote working, there might be more interest in these places, but maybe not unless there are other attractive reasons to move there besides its cheapness.  

The alternative they found is offering 3.75% which seems a little high. thanks in advance

Could you imagine if the attractive young family on a DIY show entered a home and went right past the farms sink to look under the basin. 

Mt Dora is close enough to Orlando for people who want a day two at the attractions there but also want to enjoy a day at the beach at Daytona, kayak or hike in the Ocala National Forest, or enjoy "Old Florida" history in the town.