I'm sure it'll be fine...if you're sure it will maintain those temps. If I understand right, your only source of heat is the UTH? My experience with those has been that they don't radiate heat to the rest of the enclosure very well at all. So if the room temps drop outside the tank, your cool side may drop too low.

You might consider a second UTH for the cool side. Or, if you got a CHE or Radiant Heat Panel, you could also get the overall ambient temps up a bit as well.

All that being said...if you're sure the temps you've stated can be maintained consistently, then I don't think you need to change anything.