If I needed to use a RasPi as a computer for a few weeks, I would just go to some electronics store and get a USB keyboard for 5$. But if you're buying a monitor (while travelling!), you could just buy some cheap Laptop to use.
I've been toying the idea of replacing my aging macbook with one + an M4 mac mini - the situations where I need to use the computer on battery are relatively rare, and it'd be substantially cheaper.
I even sometimes use a bigger suitcase with wheels, I can fit 2 screens in that suitcase easily and use a Dell MDS19 stand - the pro for this stand is, you can unscrew the bottom (no screwdriver needed!) and it is just a very thin flat piece. The other part is also basically just a long heavy bar with the monitor mounts, but in total it is easier than to transport the two individual stands.
Previously I have travelled with a 'normal' monitor in a suitcase and had it destroyed by baggage handlers.