It's rare for a TV to have both Freesat & Freeview capabilities, usually one or the other, but more commonly Freeview.
We had an old 12v Sky box on our boat which was slow and problematic, i replaced this with a Manhattan SX which is great, 12v and has a tiny footprint.
We also take a Firestick when we go which is fed by a 3 sim in a Huawei MiFi dongle, seems to stream fine so far. Only had one problem with signal somewhere up the Ashby, but this was solved by taking the dongle out of the window and sticking it in the welldeck (luckily wasn't raining)