I realize I never replied, but thank you! I got into contact with them and am now in the final stages of getting it all set up to start in a couple months. They seem awesome and I am excited to work with them!
Two options off-hand: Paradox’s in-house games are all linux-based. Unity does linux as a compilation target, but I understand their reputation isn’t great, and may limit their ability to take interns. Hope you figure something out!
One time I asked a Linux question in unity forums and the only response I got was something like “you people have no idea how lucky you are that unity is under contract to have a Linux version. It’s almost up though and soon we won’t have to deal with Linux questions”