Help! We need everyone's advice re: surgery

We have a five year old Cattle Dog who [partially] tore her [rear left knee] cruciate ligament two years ago while playing frisbee.
We came very close to have a precedure called "TPLO" done but we were able to wait and it got better on it's own.
We discontinued the frisbee and ball chasing [hiking everyday instead]and put her on daily glucosamine & chondritin which seemed to help.
Unfortunately, a little over a week ago, she started limping and favoring the knee and it is not going away despite a reduction in hiking and daily "Rimadyl" anti-inflammatory pills.
We have surgery scheduled for Feb. 9th. Here's where we need everyone's help and advice:
For those of you who have dogs that had the procedrure, HOW WAS THE RECOVERY PERIOD? We are told our dog will have to be COMPLETELY immobilized for 8-12 weeks [confined in a kennel only allowed out to go potty].
Ours is a VERY active cattle dog and we don't know how we are going to keep her quiet for 2-3 months when we can't even do it for 2-3 hours.
The initial week would probably be easy due to the discomfort of surgery but how do you keep a dog like her confined [& happy] for that length of time?
We are retired and will keep her company in a compfy area of our home the entire time, but we are WORRIED about the healing time and her not going NUTS being confined for such a long time. Are we overly concerned?
Please help us so that we will make the right decision for her.
[By the way, we'd love to put this operation off again, as she is NOT limping-but she does "favor" the leg after resting from our morning outing.]

Completely immobilized? My Lacey had her left knee done twice (long story) and is having her right knee done this Thursday. We were never told to keep her completely immobilized. She was allowed to walk around in the house. No running, playing with our other dog, or going up and down the stairs too much. She is a very hyper dog and somehow we managed to survive. We have her leashed outside at all times because she might see something and take off running.
Good luck with you pups surgery and recouperation.

http://groups.yahoo.com/group/orthodogs/

:( Never dealt with this, so don't have any first-hand advice to offer, but talk to your vet again if possible to make sure you understand exactly what will be required, and if he or she has any suggestions on how to accomplish the desired results. Having a vet suggest crating for that long just sounds wrong. Sorry I can't be more help. Good luck, and get well soon to your girl!