User access to multiple websites in multisite

I have a WordPress multisite containing say 20 different subsites each of a particular niche category. I want to create at a minimum two memberships:
Level 1: Free with temporary access of 1 day. The goal here is to have users manually upgrade to the paid option before being able to create posts.

Level 2: Full Author access to all subsites for $?? per month.

Is it possible to create a membership which grants registered users access to all subsites in a multisite network? The goal here is that if a user logs into say http://mysite.com/blog23/ they can do so without issue.

Any responses appreciated

Bump

Did you ever come up with a solution to this?