If you're even reasonably handy you can upgrade the internal drive on any Mac using the instructional videos and tools from https://www.ifixit.com/
The videos at https://www.crucial.com/usa/en/support-ssd-mac are also excellent.
Another source for upgrades is macsales.com
https://eshop.macsales.com/upgrades/macbookpro11-5
I haven't done a MacBook Pro but recently replaced the internal SSD in my MacBook Air with a much larger one, it took fifteen minutes and one screwdriver. The Pro may be more complicated but it's certainly doable if you follow the instructions.
The videos at https://www.crucial.com/usa/en/support-ssd-mac are also excellent.
Another source for upgrades is macsales.com
https://eshop.macsales.com/upgrades/macbookpro11-5
I haven't done a MacBook Pro but recently replaced the internal SSD in my MacBook Air with a much larger one, it took fifteen minutes and one screwdriver. The Pro may be more complicated but it's certainly doable if you follow the instructions.