This isn't an amp, it's a guitar ....
I also spend a lot of time travelling. So last week, I bought one of these:

For £109, it's pretty damn good. It needed a little set-up attention, and you'll never get away from the fact that it's £100-worth of made-in-China, but if you need to carry something small & light and not-too-valuable, I don't think there's anything better. It's remarkably comfortable to play, and the sounds aren't as bad as you might think. They also do a 2HB and a 3SC config.
The shop was really helpful too.