But you can indeed vape in your non-smoking hotel room. You just need to take a couple of precautions so as not to get caught and MAYBE wind up paying some sort of a cleaning fee.
A question was asked by a YouTuber, Vaping at Pete's Place, which essentially posed the question as to whether or not vaping would set off a smoke alarm in your room. He even conducted an experiment in providing the answer, complete with a smoke alarm in hand and at the ready to demonstrate.
In a nutshell the alarm did in fact go off. However, this was only when he blew his vapor directly into the smoke alarm. When he was at a distance, the smoke alarm was not triggered. He did mention that in some instances, if the vapor becomes too thick in the room, at some point the alarm may also inadvertently be set off.
Therein leads me to those precautions. I have been lucky enough to have hotel rooms where you can open a window. That's first and foremost. But even if you can't do that, most hotel room bathrooms do have at least a fan you can turn on, and certainly you can vape into that. It isn't totally effective in sucking all of the vapor out of the air. But the little bit that might not get sucked up into the fan will quickly dissipate anyway. So, no harm no foul there.
Worst case scenario, if the hotel were to for some reason call you after your stay and ask about any odor in the room, enough of the e-juices are either fruity, creamy, or perfumy in nature. So you could simply say, "Maybe that was my hand cream?" or something like that. "I was using a fruity shampoo," could be another response. "Maybe it was my cologne?"
Bottom line is you can indeed get away with vaping to your heart's content in a non-smoking hotel room. Just don't go too overboard as to set off any alarms, or red flags.