Thanks for these questions. The files are a mixture RAW (original untouched), PSD (layers) TIFF & JPG (delivered), Word documents, PDFs, HD and 4K video clips, finished movies and a lot of other stuff, so a bit of everything.
I guess I may want to access them to respond to requests about old projects, use in new projects, check documents when my memory does not work as well as it should, etc, so again: a bit of everything - though mainly as insurance rather than a specific need I know in advance that I will have.
Fortunately I am not as young or ambitious as I used to be, so even if I lost access to all of the files it would not be the end of the world (and as you say may be quite theraputic) but old habits die hard and whatever happens I expect that I may be more comfortable if I have some way of accessing them while otherwise enjoying being on the road.