I would recommend Peropesis to you as a minimalsitc distro but the dual booting process will not be as easy as mint you also can try to use a distro with xfce desktop environment but I would say that 30 GB aren't much anymore and you should think about upgrading
I'm currently using Nobara a Fedora fork and upgraded today to version 38 it was a bit of a stretch. I had to delete many things in my /etc/ to get GNOME 44 working. Bluetooth and the panel on the top right is a bit buggy but it works.
I would recommend Peropesis to you as a minimalsitc distro but the dual booting process will not be as easy as mint you also can try to use a distro with xfce desktop environment but I would say that 30 GB aren't much anymore and you should think about upgrading