> One useful additional aspect to Tailscale that I've not seen mentioned so far, is the integration with Mullvad.
Indeed, this saved my butt earlier this year when I was at Qatar airport and they tried to MITM most of my connections (including to mullvad.net). Luckily, they didn't MITM tailscale.net, so I could log in, enable Mullvad, and thereby secure my entire traffic.
Are you sure they weren't just trying to redirect you too a capture portal?