I would have the buyer wire the funds. The title company can verify with the buyer's bank that the wire has been initiated. You can also ask the title company to hold the keys until you receive proof that the buyers have initiated the wire at their bank. If the buyer initiates the wire in the morning then the funds should arrive at the title co a few hours later or at least the same day. Unless they are dealing with some stone age bank the wire should only take a few hours at best.
I had a funding delay once because the closing was on a Friday and the buyer waited to late in the day to initiate the wire. So the transaction was funded on Monday. Since then I try to avoid Friday closings, because if there is a glitch then you have a weekend to wait it out.
These out of state buyers should have also received a preliminary HUD (closing statement) via email so they know the amount needed for the wire. Unless they do not use email which would be rare these days. So really no need to delay funding on their end as long as they have the correct amount to wire.
