Sorry for the delayed response everyone, you know how holidays can get! Anyhow, thank you all so much for your replies, this is giving me a much better idea of what to expect and what I should do. I was on the fence about RHPs because of the contradictions I saw, but I think I might go for it when pay period rolls around. I can't thank you all enough for your help!

To the insulation on the top of the cage comments, I have a few blankets up on top that I kept there in hopes of keeping her warmer, I can add cardboard to that as well if you all think that might help hold in heat a little better. That custom cage is incredibly well done, it looks so nice! That front overhang is a good idea, I might have to snag that.

Right now, I have an empty T8 in another room that I can use to test and see how it might do with making a hot spot all on its own and see roughly what to set the thermostat to in order to have it reliably doing what I need without bugging Cinnamon Roll as much. I've been testing things on that one for awhile trying to get it to a good temperature without the portable heater, and hopefully this will be the one to do it.

Thank you all again so very much, this forum is always incredibly helpful! Now I can sleep a little easier tonight with this information.