I use termux to host a jupyterlab instance and bring along a tiny folding bluetooth keyboard. Even in airplane mode I can connect to the locally hosted jupyterlab instance. Notebooks are kept in git and synced up to my private repo when I'm back on grid.
There are simpler solutions for writing, but this allows me to keep a single workflow across home/travel contexts. Being able to run graphs, basic code and computation as needed is also a plus.