It's sad that if you want a fast Internet around here you are put behind ISP wide NAT which means you can't host anything from home, so all these "self-hosted" things aren't really self-hosted for me.
I'm not ISP locked, but no other ISP offers me anything else since: "we don't offer worse service since we can offer you faster connection via TV cable".
Your VPN provider can probably MITM that much like your ISP could but not without messing with the certificates that you're pinning.
You shouldn't have to do that but given the circumstances it'll work. Whether you can be bothered is another discussion.