Sure. I think with LVM you have decoupled your partitions from their physical location on the disk. You could shrink and move logical volumes around, make some (free) space for a new one and install a new distro on it. Or just replace the PopOs root with a new operating system.
As I remember it's not super easy but there are quite some wiki articles about LVM and guides on how to shrink/change LVM volumes including the filesystem inside. LUKS+LVM+ext4 is a pretty common scenario.
However... Having a Backup of important data is always a good idea. Especially when playing around with partitions and filesystems. And more so if you don't exactly know what you're doing.