Not all suppliers cap use abroad … ID Mobile a UK has no capTBH, we mostly rely on our satellite system.
Unless you install/sign up to a VPN you won’t be able to watch UK channels with a foreign SIM. If you use a UK SIM you’ll most likely be limited to between 12 & 25 Gb/month.
There are a number of existing threads on which SIMs are best at any given time. If you use the search facility you should be able to find them.
Ian