I was wondering if you could still book ship passage places easily these days (without it being a cruise, which is another possibility for select routes), and came across someone talking about booking rooms for ~$100/day (including food) on cargo ships.[1] Seems like it takes ~7-10 days to do a transatlantic leg of a route, so it would definitely take a while (and it has very limited routes, so some flying or overland travel might also be required for many routes), but it might be an interesting way to take a vacation before or after a business trip.

1: https://matadornetwork.com/notebook/how-to-travel-by-cargo-s...