There aren't many Brits in my area, although I do live in a college town, so I suppose the population may be more cosmopolitan than similar-sized towns in the corn belt. Anyway, my local supermarket stocks PG Tips, Marmite, Jelly Babies, Weetabix, digestive biscuits, Birds custard, Robinson's lemon barley water, Heinz beans, Rose's marmalade, etc. etc.
You might think this would alleviate the homesickness, but in a weird way it accentuates it.