Upgrade ssd for bootcamp?

I am trying to boot camp my mid 2014 macbook pro 128gb. currently i have about 50 gb of free space, but i am still getting "not enough free space". i understand i should at least have about 55 gb for it to proceed?

i don't have time machine on, i also don't know why my system is taking 55 gb either.

The only thing i plan on using windows is for solidworks, as it is required this semester. my plan is to upgrade the OWC Aura Pro X 240 gb.

would this be my only option?