Really doesn't sound like there's much to be concerned about- just keep an ear on it. As far as raising the temps. for a suspected RI, usually only a couple degrees is what is suggested (as long as you're not already at the maximum for safety).
I see what you mean- space heaters can really make ambient room temps. fluctuate- making snake enclosures more of a challenge.
Since we're not seeing or hearing your snake, only you can decide if a vet visit is needed. But I could understand waiting for something more definitive in the way of symptoms- otherwise the trip might be a waste if it's something too subtle for the vet to observe. And don't forget that antibiotics as well as the stress of going to the vet are not without negative side effects- you want to be sure it's needed. "First do no harm" & it's certainly not an emergency right now.