I run LinuxMint MATE on my desktop and have done so for years. If I need a LiveCD/LiveUSB, I just use my LinuxMint USB install stick.
I also have a complete system installed on a 64gig or greater USB stick, as a portable backup system. But I have rarely used it. I say 'stick', but it's a tiny little flat tab thing about 2cm by 1cm by 1mm. (looks a bit like two micro-SD cards stuck end to end.) It lives on the key-ring holding my bank-fobs.