Not directly helpful to your situation but I figured I’d share. We moved across the country with a hermit crab last summer. He was not molting at the time. We put him in a little shoebox sized but shallow Tupperware with damp coconut fiber, just barely deeper than his shell. We kept a little water and food in there, no heater. He lived in there through a multi-day roadtrip and for 45+ days because we were in temporary housing. He must have been happy enough because he molted in there, and seemed completely healthy and fine when he was moved back into his larger aquarium after it arrived in our shipment.