What puzzles me is your reference to the "/boot
partition." I am uncertain why you would want
220 gigabytes in that
is normally the smallest partition, because all that it needs to have is enough space for grub
and a couple of kernel-images (the one you're using, the one you just built, and maybe the one before that) and their related files.
Personally, I've grown rather fond of having multiple partitions ... ones that are "entirely separate in every way" from the root partition and its contents. Great places (hint, hint...)
to put backups of everything important. Stuff like the contents of /home, /etc/, /lib.
If I were you, finding myself with 220 gigabytes of storage just a'burnin' a hole in my pocket, I'd keep it as a separate partition. Maybe two. Three. I might even hold some space purely in-reserve.