I set up a similar situation with my heatpad on top of a hide to keep it warm. I'm using a safe human heat pad since I can't detach the under tank heater from his tank, but when we've needed to travel in the car he has seemed to like this heat pad I'm using so hopefully it will work.
I am glad it worked for your snake but I REALLY hope mine doesn't stay in there for 14 days. We're on day 4 now and even knowing he's just right inside the cabinet I'm still so stressed. Thank you for the suggestion and information!