No riding in the next few days is going to help you on Saturday. I'd follow the advice of others in this thread, and go for a 30km ride today (little late, sorry) or tomorrow, then rest on Thursday and Friday. 30km is enough to see that you are as well as you think you are, without exhausting you.
If you then have any tweaks to the bike (eg new chain or tyres) then go for a 10 or 20k ride to make sure everything is ok.