I'm having a problem with my 2001 XC-70 (114,000 miles). Rough shifting in low gears at low RPM's. Yesterday I got the "Service Transmission" alert and it went into limp mode after a long slow uphill drive. Dealer says it had a TCM-0100 error code and needs a new transmission ($6K new). They say I can drive it till it fails before I replace it. I've read a lot about this code on various forums but nothing very current nor conclusive.

So here's my questions:

1-Is the tranny toast? or is their a less expensive fix?
2-How long do I have till it fails completely?
3-What are other common problems with this model year to help decide if replacement is worth while? (I've done quite a few of what I hear were common repairs)
4-What are opinions on rebuild vs. new?

Other than this problem the car is in great condition so I hate to scrap it now, but $6K is a pricy repair.