Originally Posted by
ProleOnParole
The good news is LibreOffice documents are saved in an open, XML-based format, and someone has most likely made a native Android app for editing them. If you want to go the Android way, I'd research this option. Alternatively, you could use Android as a thin client to remote desktop into a server, where you have all the applications set up: this I'd only recommend if you always have access to a reliable network connection wherever you travel.
One "think outside the box" solution would be to carry a really cheap mini-desktop like a Raspberry Pi (might need a wireless dongle and SD card), expose a private AP, and then connect to it via remote desktop (or VNC, or X2go). The Pi (or similar things) run off USB power so a decent sized USB power bank could run it when not plugged in for at least a while. I'm not sure whether any of the tinier travel routers have enough CPU to do a decent job with LibreOffice+VNC but that could be an even smaller option.
This wouldn't cost much, wouldn't take much weight, and while it wouldn't work (or at least be officially allowd) on a plane, it could be used almost anywhere else. It still sounds more inconvenient than just getting an small/inexpensive Chromebook or PC laptop and turning it to either dual-boot or just straight over to Linux, but it's a fun idea to contemplate and could be done for well under $100 all in.