I’ve used closetbox.com for this in my situation. I’ve had my stuff there for years. They aren’t traditional self storage and keep my stuff in a big wooden box a few floors off the ground in a temperature and humidity controlled warehouse so I don’t worry much about things getting damaged. I have been back several times to drop more things and have verified they take good care of my stuff. Pricing is reasonable. Roughly $200 monthly for a two bedroom apartment worth of stuff in Southern California.