I ended up buying the cheapest Steam Deck, and then replacing the internal SSD with a 2TB one, partitioning it to install both Steam OS (smaller partition) and Win10. Now it pretty much runs everything, and can also remote play the PS5.
It is a nice machine and it runs most stuff well, and as you say, ergonomically very comfortable. The battery life is not great, but I just use a decent external battery, but on your commute that may not be so practical. I will install Office and a few other apps on it, and need to setup the Emudeck stuff for some old games.