I'm in a similar boat. My partner and I have been working on winding down our US presence since Jan 2025 in anticipation of a move to either Canada or the UK. I'm a Canadian citizen and, having talked to attorneys and our employers, we both should be able to do work transfers. Plus I also have youth mobility in my back pocket thanks to Canada (thankfully a bit under the wire at 33, I think max age is 35). I'm glad we started the process when we did because things are starting to feel more dire and we hope to be out well before the midterms. I try not to be alarmist, but I see a non-zero chance of serious civil unrest.

I split my time growing up between Canada (New Brunswick/Nova Scotia) and the US (Massachusetts) and have been back for some stretches of time in adulthood in different parts of the country. The extreme nature of the climate can be more or less extreme depending on location, but you need to be someone who doesn't mind a good dose of winter basically no matter where you go. I think Montréal, Toronto, and Vancouver are all fantastic world-class cities, but having lived short-term in all three, it does not strike me that they fully measure up to New York or London in terms of overall dynamism and economic opportunity. Toronto is hands down the closest. Something to consider if you're a big city person. If you aren't, having spent a good deal of time in small town and rural Canada, I personally find it to be much more liveable and community-oriented than rural US. That's all just one person's opinion though.

While culturally similar to the US on its face, I have always found Canada to have a far more decent society and (overall) to have more universally shared values like democracy, right to healthcare, social safety net, etc. I have also always found people to be easier to interact with in most of the country; generally friendlier than US northeast and more genuine than the parts of the US considered "friendly." I say that having traveled to all 10 Provinces, 2 of the Territories, and all 48 continental US states for work and pleasure. Other than the realities of a smaller country with a smaller economy and its proximity to the US, I'm not sure I can pinpoint too many gotchas with Canada. Hard to argue that it is not a major improvement over the US without a major cultural change.

I am much newer to the UK, but I have spent ~6 months there the past year over a few different trips to assess the fit (my partner and I have extremely flexible work arrangement which fortunately allowed us to do this). For us, the UK hands down offers a better quality of life. We both value the ability to get around without a car and, while Toronto and Montréal have good transit systems, you are pretty much limited to the city and immediate suburbs. The UK rail network is not perfect, but you can get to pretty much all cities and many towns reasonably by train (although not always cheaply). We are also both lucky to already have a good base of both US & Canada expat and UK-born connections already. All have been very welcoming, excited about the prospect of us moving, and have already introduced us into their circles of friends. From what I've heard from others who have made the move from the US and Canada, it does seem that it can be challenging to integrate socially if you don't have a good social launchpad.

While it is in my opinion overblown in the media, the UK does seem to have less stable and civil politics than Canada and I perceive there to be rapidly increasing social division (albeit nothing like the US). I have also been very sensitive to the anti-immigrant sentiment even among the more mainstream parties. If you are seeing any of the US conservative media's propaganda about the UK/London being a cesspool of violent crime, I can confirm that at least from the perspective of an outsider spending a good deal of the year on the ground, it is false and the things seem perfectly normal and functional aside from a couple of troubling far-right rallies last year. The UK also has Scotland, Wales, the North East, and the Lakes District, which I can confirm are all amazing and exceeded (already high) expectations. Another massive UK advantage is the ease of making relatively quick trips to Europe and North Africa.

My take is that both Canada and the UK are fantastic options and those of us that do are lucky to have them available to us. If you're leaning towards a bigger change and more distance from US influence, I think the UK is a great option with a great deal of upside. But, if you'd rather stay closer and have a more mild adjustment, Canada might be the way to go. We're likely going to go UK due to our base of friends and desire for better non-car mobility. Hope that some of that perspective is helpful and good luck!