I would put on hold for the year and re-consider after the November election. That will tell you a lot about what the future may look like and you can have a few more months perspective to make a decision.
I'm American but left almost 10 years ago (live in the UK now). You couldn't pay me any amount of money to return. Not even for the experience for living abroad (there are plenty of other nicer places to go anyway). NYC is great (lived there for many years in my 20s), but I wouldn't want to live there with dc unless you have lots and lots of money. I mean a salary in the 200K+ range. Or your employer will be providing housing and very good health insurance. It's also really expensive. I mean all of America, not just New York. Except for fuel. That's cheap.
But a lot of it is down to cultural differences. Even as an American, because I've lived abroad for so much of my life (not just the UK, but other places), I find it really hard to adjust back. People are rude and pushy and sort of obnoxious. I don't mean everyone, obviously, because I have lots of friends and family in the US and many of them are individually very nice. But just the way people speak to you in shops or in public transport or people you stop and have a conversation with. I mean in a really general sense, people aren't quite as easy to deal with as they are here.
The political and religious beliefs are also really difficult to deal with unless you yourself are quite right wing. It's always been this way relative to other places, but I would say it's gotten much worse in the past 12 years or so and certainly much, much worse since Trump.
I just wouldn't want to live there again. I don't even like visiting that much. But I would say in normal circumstances, a year in NYC would be great, assuming you have the salary and the housing options to make it work (and can afford private school). I wouldn't do it now though. The economy will be changing significantly in the next few months in the US and unlike here, there is really very little social safety net for most Americans to fall back on, so times will be very tough there. If things settle towards the end of the year, I'd consider it then. I work in central London and I don't even know that I'll be going back to my office until September or so, so there surely isn't too much rush and you could continue to work from the UK.