You just need to figure out the power requirements of your camcorder, then the amount of reserve power you'd get from the UPS. You can figure the watt output of the UPS to be 60% of the VA rating. I don't know what your transportation details would be, but if you have to lug that UPS on foot, size and weight might be a consideration.
I plan on shooting many hours of video in remote locations, without a means of charging batteries (Canon Vixia HF M500). I could pack in a small battery backup/uninterruptable power supply, like the one I have connected to my desktop PC. Any problems in running a camcorder off of such battery power?