as long as the temperature doesn't stay 85 for too long you should be fine. where i live the outside temperatures are constantly changing from 95 to 60 (obviously not those temps. in the enclosure) the next day, so my ball python's enclosure is also constantly changing. fluctuating temperatures are normal in the wild, so a little bit of it in captivity should do no harm. (as long as it's not 85 or 90 for days at a time on the cool side). however being 2 or 3 degrees warmer than normal should be fine. so i think you should be good to go, just keep monitoring the temperatures to make sure they aren't too warm or too cool.

if the temps are too warm you can put some wet paper towels with ice on top to help lower temperatures. too cool, get a heat lamp to raise ambient temps.