I don't know any outfitters but suspect it'll be tough to come by one that flexible. I think you'll have to make some phone calls and talk to several personally to see if that'll work.
Where are you coming from? Travel will be tough. Last minute flights will be a gamble and driving may not be possible if you have very far to go.
My brother farms some and works in the age industry. His busiest time of year is spring, so he's never had the opportunity to come hunt Merriam's with me.