Verizon phones are pretty much all unlocked. We don't use Google Voice so we'd get a new GV number for the Pixel.

However, after poking around some more, FT helped me find what I'd spent hours trying to find with Google searches: a reasonably priced data SIM card that can be installed while at home and works in many countries. That would be FlexiRoam. For $36 including shipping, you get a sticker that goes on your SIM card so that you can switch back and forth from your carrier to Flexiroam at will. The price includes 1 GB of data (about what I'll need) that is valid for 90 days, and when I travel again, I use the same sticker and just buy another $30 1GB plan (so in that sense it's easier than swapping SIM cards). So far people seem to be happy with Flexiroam, and it would cost roughly the same as Fi without all the cancel or suspend hassle.