Note: the growing the partition from a live USB thing is only necessary if you want it all to be one partition. If it’s a separate drive, or even if it’s not, you can just format the old Windows partition/drive and mount it as a new storage volume.
NixOS is amazing, but it’s also got a crazy learning curve. Once you grok it though, it really changes the way you configure your computer.
Fedora is always my favorite big name distro, they’re constantly pushing the envelope and adopting new features that need some stability and exposure to mature.
Sounds like you could benefit from NixOS ;)