I think it depends on what you are rooting. We root cuttings under lights in the basement. Usually it's in the 70's down there, and we always did reasonably well with most roses. The notable exception was teas and chinas, which probably did want more heat. Then there are the people who claim gallicas are hard, probably because they are rooting them with too much heat.

"NOT" warmer !
70 to 75 max.
Check out my Own Root Cuttings Setup Gallery with detailed comments and info for each of the 30 images.
Link below.
George Mander

Here is a link that might be useful: Own Root Cuttings Setup Gallery

I have more success by rooting roses in October before the first frost. I root outdoors but have no shaded area so as a result of wainting until fall the daytime temperatures are less intense and so less burning is a result. I do use
gallon size clear plastic juice bottles with the bottoms removed and mulch piled high around them.
Just be prepared to drink a lot of fruit juice for a while.
lol

Listen to George! Last year my son (5 yrs old then) was in the basement playing, and turned up my thermostat on my cuttings to 85 degrees. They about cooked in the 2 days they were at that temp! My thermostat is set at 73 degrees and this seems to work great! Right now I have a ton of cuttings down there. these include;
Jennifer Hart
Kentucky Derby
Razzle Dazzle
Summer Fashion
Tribute
Merci
Bright Delight
Be Glad
Moonrise
Rejoice