If it were me I'd pick up a half dozen live mice so you don't have to keep making the drive and keep them in a small tank with food and water bottle, maybe pick up one of those small scientific cages where you can feed rodent blocks from above. Mice stay pretty small and most likely won't outgrow your snake, and won't need to nurse like a rat pup. Try to get all females so they don't smell. I'd first try a fresh killed mouse euthanized with CO2 followed by a frozen thawed in the same feeding to see if you can convert. If the fresh killed doesn't work I'd wait a day or two and feed a live mouse just to keep him growing then try again with a pre-killed the next feeding. It helps to have multiple snakes so the uneaten rodents don't go to waste. You should be able to get him converted but I wouldn't stop offering live and putting him on a fast.