In my experience ZooMeds run hot, way hotter than my exo terras, do not run wide open. I recently got a BP (my 1 yr old normal) that never had a UTH, and she was fine if not a little small and lazy. My advice it to unplug until you get a device to control it, and use a lamp or CHE or something else to keep ambient temps at about 80-85F. A dimmer works just fine if the room or house doesn't have much fluctuation and is thermostatically regulated. If not you will be in there multiple times a day adjusting for room temp changes. Right now we don't have the heat or A/C on (so we are quite cool at night and warm in the day) and I have my new BP in an enclosure with a UTH on a dimmer (my 1 yr old has a hydrofarm), and I can tell you that I am in there many times a day adjusting. Luckily I'm a stay-at-home-mom, so it's not a big deal, but if you are gone during the day, just spend the extra $20 or so and get a cheaper (on/off) thermostat like a hydrofarm (check amazon). Or if you can afford it, go for a herpstat (around $100 and up), or equivalent pulse proportional thermostat. For the record, I do intend to get another thermostat soon, just waiting for them to go on sale (at amazon.ca) again, but until then I have to be extremely vigilant.
As for using layers to insulate, I wouldn't bother, it will still fluctuate unless the room is super stable, and it's way easier to adjust a dimmer than it is to go in an remove layers of insulation multiple times a day. Your BP will be fine until you get a dimmer (or better a thermostat), just get on it and don't let him get too cold.