Contabo. They've supported IPv6 for a decade now based on the date on their instructions (https://contabo.com/blog/adding-ipv6-connectivity-to-your-se...). Enabling IPv6 comes down to copying "gateway6: fe80::1" to your netplan file, adding the /64 listed in the control panel, and optionally adding an IPv6 DNS server. After a reboot (or sudo netplan apply) you'll have full IPv6 connectivity.

Well, their default images come with a script that'll allow you to `sudo -H enable_ipv6`, but I removed their customisations so I had to do it manually.

They have raised their prices since I last ordered a server there, it looks like €5,45 is the cheapest server you can get these days (includes VAT of course).

Terrific, thank you.