Yes, you can do even more, you can put all those user data to some offline storage as long as you can justify that you need this (which is very often the case).
GDPR is mostly about processing user data, not storing them. So user can execute "right to be forgotten", so the data will not be accessible in any way and you are not allowed to process them, however you have full right to keep those data if you believe that this user might show up five years later and try to sue you for a, say, undelivered order, etc.
In that particular case you need to be able to prove that user wanted to delete the data. Otherwise user might sue you that you've deleted those data without agreement and caused some business losses in that way.
Someone third party might also show up and accuse you that you deleted data as a part of conspiracy with the user (think of angry former wives/husbands).