The UTH would work great for summer as you mentioned. I have to use a RHP all year round because I keep my home at 68 with AC during summer and Heat to 68 during winter. I cant stand being warm when trying to sleep.
So in my case the RHP gives me my ambient in a 68 degree house and a Basking area which you will already have your ambient during summer so the UTH will give you your Basking. The only thing is that you will have to keep changing probe placement or get a Herpstat2 and keep both hooked up all year only running the source you wish at the time.
Heat tape is cheap enough but Id just keep both hooked up and run a Herpstat2 because Ive had problems with taping and un-taping heat tape in the past. Its pretty thin and a short is the last thing you want. Best of luck and have fun
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