Popping in because I have watched this thread, seen a lot of things, and feel the need to add some personal experience and advice.
Hoggies will try to auto-brumate if the room gets a little chillier and your heat doesn’t keep up. Mine are currently on their little winter hunger strikes right now. I use whole room heating and not enclosure heat, which is why they do this.
Something to keep in mind is that your enclosure is a microclimate. Just because your room is sitting at 74-76 doesn’t mean the enclosure is, too. If you’ve got windows, drafts, anything like that can impact what temperatures they actually get.
A lot of the suggestions against UTHs are, well, opinion based. They work great so long as the UTH is on the outside of the enclosure with the thermostat probe sandwiched between it + the enclosure surface. You do need a 1.5-2" minimum gap under the enclosure to allow air flow if you use a UTH, they cannot be without that gap or they are a hazard. If you want to use one, cool, if not, also fine. CHEs are great, too, and I find they work better for enclosures with deeper substrates than lights do, imo.
As for reading they shouldn’t get below 70º, please remember that while these are captive animals, they’re still wild and nature doesn’t come with a thermostat. We’ve got Hognoses native here in Minnesota where I guarantee the winters get far below that 70ºF mark! Along with that, they take brumation cues from more than just the temperature, so also light cycles, pressure changes, etc. My rules for a non-eating winter hoggie: wait them out while monitoring. If raising the temps doesn’t get Norman eating again, just keep monitoring his weight and activity levels. So long as he doesn’t start losing a significant amount or displaying really worrying behavior, there’s really no reason to worry.
Tbh I think sometimes in trying to help, we can occasionally go a little too overboard with trying to “fix” problems that might not even be problems. To me Norman sounds like a typical hoggie in cold weather.