You are really looking for an answer that honestly cannot be given. I know how you feel and it is an easy question to ask, but no one can really answer it.
The correct answer is, if your tranny is giving you problems then take it to a shop ASAP and get it looked at.
Do we all follow that? NO! Should we? YEAH!
I am currently having tranny problems myself, but I know that mine are not that overly serious so I am driving. I have gotten around 3000 miles on mine. But keep in mind that my problems are not quit as serious as yours. My problem is a torque convertor clutch system malfunction and pretty bad case leak. It is also leaking from around the pump houseing. I do not have the money to send it to a decent shop and have it rebuilt the right way, so I am buying a 2000+ used tranny and installing it myself. Save my money and get the old tranny rebuilt and either sell it or keep it as a spare.
If you can get a spare ride, then use it! By all means take advantage of that! Your tranny issues will eventually put you down on side of the road in a neighborhood that is not the friendliest and everyone there will want pizza! LOL!
