To avoid having to try to ride on Zwift while actually out on a road in real life in a presumably unfamiliar country (!), it might be worth the extra cost of ordering a cheap dumb trainer and having it delivered to where he’ll be staying. (Without a fan it would be workable, but it’s going to get hot fast.)
But @Jack_Nosco, tell us more of the practical situation. Are you arriving empty handed (as it were), or will you have some cycling equipment with you? Will you be staying in a hotel?
You can probably bring a small dumb trainer or portable rollers to use, and your bike. It would be helpful if you could specify what you are bringing, and what you don’t have/aren’t bringing.