Aight, a few suggestions so you can have something approaching a decent cup.

Assuming you're stuck with bags, which isn't the best tea, how you heat the water only matters a little and you can get a fairly similar state with a microwave.

Nuke the water twice. It's going to vary depending on the microwave, obviously, but this the low powered stuff in most hotel rooms, go with 1:30 twice. The water should be just under boiling after the second zap. Stir in between, then stir before dunking bags. This also assumes a "coffee mug" sized vessel, which is usually about 8oz (y'all brits still use those liquid measures? I'm not sure, but I can calculate the CCs if you don't have access to an app for that). If the cups are smaller, maybe do two one-minute zaps and check the temp.

Now, if you've got loose tea and your own steeper, it's about the same, but you can go a little hotter (more hot? My brain can't parse the right grammar) since the steeper will suck up some of the heat, and do so quickly.

Tbh though, the difference in nuked tea and more properly steeped is likely moot if you're using the bags the hotel provides. Most of those are utter crap even by US hot tea standards.

That's also assuming the front desk doesn't have kettles. They aren't usually in rooms, but some places do have them available on request, particularly in cities, and even moreso in cities they have a lot of European/British visitors.

You'll likely need to warm the cuppa