I tore my ACL, MCL, and lateral meniscus back in September. Scheduled my surgery for December, and in the meantime I took it easy to let the swelling go down (swelling+surgery=nono) and MCL heal (mine was a grade 2/3 tear).
Depending on the severity of your MCL tear, it may be left to heal without surgery (seriously though, take it easy, you don't want it healing loose). ACL will be operated on, and the doctor will probably trim/stitch/do whatever needs to be done with your cartilage then too.
A grade 2 (half of fibers torn) MCL tear can as little as 6 weeks to heal, but the ACL rehab is going to be the bulk of your recovery. The MCL, lateral meniscus and medial meniscus injuries shouldn't make your ACL recovery significantly longer than the typical 6 months, if any extra time at all. In the end though, it's down to how fast your body heals and how much you put into the rehab. It won't be any less than 4 months at the VERY MINIMUM (3 months = new ACL is weakest).