I don't use my furnace in the clipper, but I just bought this thermostat for my house wall gas heater and thought it would be an easy mod to update a clipper:
https://www.amazon.com/gp/product/B015Z486SI/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1 (https://www.amazon.com/gp/product/B015Z486SI/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1)
It runs on 2 AA batteries only - no pull from your house battery. It is 7-day programmable with 2 to 4 settings per day. I was thinking it'd be great to set up so the furnace would kick in 15-30 minutes before you get up and warm things up, then knock off during the day while you're out playing, then kick in at night before you pack in for bed, then knock off during the night while you're sleeping. No having to fiddle with the controls and you could set your preferred temps and never worry about it. There's an on/off switch also so you can shut it down when you're not using the clipper.