The practicality of that may depend on the exact details of the modem. For example, I believe it's possible to get a fairphone in the US, but last I checked it was a poor choice because it had awful support for cell frequencies actually in use. This lists "global roaming modem configuration" which may mean that it has good coverage, but... it also might not.
>>yjftsj+(OP)
Jolla is saying they'll try to make it work on as many frequencies as possible for global support. I don't know the brand and how seriously to take that but usually English-speaking countries support are among the top priorities