The issue is more likely to be your port selection and UDP being discarded on networks with captive portals that generally only allow certain ports and traffic. Try using some other common UDP service ports like 53/DNS if not already in use, or maybe 5060/SIP, or even other common VPN ports.
Unless they’re running L7 hardware in the hotels, I doubt they’re doing any kind of packet inspection.
You’re asking for a lot of different things that don’t align, so instead of trying to guess what you need, let me just throw a few things out there: