You shouldn't need to I don't think. You may just need to adjust your dimmer.
If the UTH is affecting the ambient temps then it's way too hot and definitely dangerous to the animal. It really should only affect the temps immediately above it and in the hide/are above it.
So you may need to do a little trial and error and get the ambient right, but regardless of the UTH situation, your lamp should be dialed in to get you the right ambient temps. Once it's dialed in, you can leave it even after you get the UTH set up with a tstat.
You're on your way. I promise it gets much simpler once your setup is right and everything is dialed in. Then it's just maintenance. At that point, just make sure the equipment is running properly and you're good to go.