My family doesn’t celebrate it (bc we never did growing up in the UK), nor do I begrudge anyone their freedom. Anyways, happy independence day y’all. If you need me I’ll be sipping tea in the middle of a wide open field wearing my ceremonial red coat.
In your shoes I’d be probably pissing nationalists off by saying “it’s a government. A government is a fucking abstract tool, not a person. I don’t commemorate the anniversary of a government, just like I don’t commemorate the anniversary of a screwdriver or a piece of software.”
If however you’re looking for something a bit less socially disruptive, probably “I’ll chill at home.” is your best bet.