Thanks everyone for your suggestions...
I ended up watching it in the Lord Nelson - to be fair, it wasn't bad at all. A few other blues in, but we were definitely out numbered by reds - no trouble though.
Only (very minor) issue was a group of 3 lads sat on the table in front of us who got touchy when I said to my mate that Ten Haag looked like a twat because he's wearing a suit with trainers and no socks. They questioned why it matters what he's wearing, and asked why we can't win graciously - then proceeded to talk loudly about how city is a club full of paedophile coaches (referring to Barry Bennell) - so I told him to lose graciously.
There was also a City fan stood behind me who announced early on that he'd had a bet on 5-1, 6-1, 7-1 & 8-1. When United scored their second, one of the same 3 lads turned round and started trying to get a reaction out of this guy because he had lost his bet. I guess it's the little victories, eh!