There are places in the UK to get an FAA class 1. The last time I got one done here it was by a company called Centreline near Gatwick - I'd suggest taking nobody's word for your ability to get an FAA class 1, until you actually have an FAA class 1.
Definitely worth looking at the Canadian options, and also going all the way down the line seeing if there are workarounds to get a CAA class 1. Heck, most people who've worked in both countries would pick Canada in preference to the USA as a place to live and work.
And if all else fails, there are other jobs in aviation: I've done several ! During Covid lockdowns my PhD in airworthiness made me a lot more money than my CPL.
G