Bruges and Belgian beer! Maybe we were separated at birth? Lol maybe not.
I love Belgium and have had many hundreds of their wonderful beers. We used to drive a lot to Belgium, and fill the car with many bottles from Carrefour. Not so much now as i can order Belgian beers direct quite cheaply and Tunnel problems, car getting old, etc etc.
I like Bruges, but it is very touristy. I've also visited Tournay, Ghent and Kortrijk... Which were all lovely and a bit more Belgian imho.
You can get Belgian beer in London, but its not always cheap.
Most places sell Duvel and Leffe but that's low end stuff. Then you have stuff like Delirium Tremens sold by some M&S and Westmalle and Karmeleit Triple sold by Waitrose. All around £2-3 a bottle.
Then you have Utobeer in Borough Market with many more of the unknown (in the UK by most anyway) beers, going up to 11-13% alc. (stronger the better and nothing like UK 'strong' beers like Special Brew or Tennants Super) but the price ramps up dramatically to £4-5 a bottle.
I'm fiercely British and would defend our glorious country to the end... God save the Queen! But much as it hurts me to admit... The Belgians make better beer than we do.
That said, we do still make good beer and 'craft beer' is becoming far more widespread now. Little companies making small batch local beer, sticking it in usually simply labelled bottles and selling it locally for a sensible price. If you decide to stay in London... You could experiment with those... A dozen mixed bottles in a coolbag, a rug, and some party food from M&S... Find a nice day and a quiet spot in one of the Royal Parks or on Primrose Hill and settle down for a few hours people watching. Lovely. Drinking in parks is fine here.
*** EDIT: Apologies, it has just registered what time of year you are going, and whilst nice weather in Nov isn't unheard of, planning a picnic may not be wise :o) ***
You could also consider a Brewery tour... Meantime Brewery in Greenwich or Fullers Brewery in Chiswick... Both easy to get to.
Have a great time whatever you decide.