Honestly thats a good reason to feed live. I would suggest at least prekilled though.
One thing to consider though is this... if you have the freezer space, maybe buying frozen in bulk ? You should be able to stock up on almost a years worth of frozen rats and could do it in one shipment ( invest in a good vacuum sealer and bags ). If the snake started outgrowing the size you ordered, just feed him 2. Im just thinking that there cant be that many places to get quality mice / rats in rural Wyoming. If your supplier runs out, then you will be back stuck trying to get him to go back to f/t.
Even if you couldnt find a shipper, there are several surrounding states that have reptile shows. Maybe try to find one within driving distance ? Make a day out of it... Frozen are so much cheaper than live that you would probably make up the cost of gas just on that alone.
Just my .02