I am looking for a way to block out all US IPs, ideally via a browser extension like uBlock Origin or a custom DNS server. I want to use this as a simulation to verify that I can still do the most critical activities without immediate US reliance (e.g., doing a bank transaction, contacting my family)
Does such a thing already exist?
That lets you test that you’re not directly connecting to US servers, but doesn’t confirm that the services you talk to aren’t talking to US servers. It’s a good start, but you’ll need to validate those seperately.
Depending on your OS, you might want to just add as many US IP blocks as you can find to your firewall. It looks like there’s a list here, but it’d be worth validating it against other sources too.