I had my ACL replaced and some miniscus removed at UNC in Aug 2001. I was back to biking in December, lightly, and rode Cycle North Carolina without any trouble in Oct. I would say 6 months is reasonable.
Im not sure what temp1 is refering to. If you're going to have it replaced who cares if its torn partially or completely.
I tried physical therapy prior to surgery and it gave me a strong leg with a torn ACL. Not much help. If you try to put it off you could end up tearing your miniscus since the mechanism to hold the knee in place is ripped and your knee will not be as tight as it should be. This is bad.
6 months sucks. Oh well, these are the only knees the good Lord is going to issue you so you might want to take good care of them.
Dave