See here the section for travels
https://darth-coin.github.io/beginner/pay-with-bitcoin-en.html
Also you can request to https://shopinbit.com/Premium-Services/Travel-Agency/ to pay for you to any flight.

I think Bitrefill still has flight gift cards through Flightgift

You can try https://www.bitrefill.com/travel/?hl=en

Yeah they died... I've used Travala quite a bit, works great!

Hope they last, and that we might help in any way to keep them growing...

I think Cheapair (or maybe the other one) was a small, established travel agent that started accepting Bitcoin and crypto?

This is a viable way forward in many jurisdictions, not hard to help an existing company to get started, that way we'd have alternatives...

Actauly I have not but I would like to read comment