As far as I know, site moderators can give at most a month long review ban manually via their tools.
Is this possible somehow to give a longer review ban?
Is it theoretically possible? Sure. It's just a date field in a database table, we could set it to December 31, 9999 if there was a need for that.
So far, there hasn't been a pressing need for that. I would strongly encourage you to avoid creating one.