A couple of things happen in fail safe mode. The ECM runs the pump pressure wide open to prevent slip. That also increase the TC lockup pressure to max, to prevent slip. Once this happens, the ECM remembers this condition and maybe assuming that the pump pressure needs to be operated higher from now on. If that is the case, it should eventually figure out everything is OK and go back to normal. I would change the fluid (especially if it smells burnt), maybe reset the ECM, and see if things settle down. I realize you are out on the trip, but I think it is worth it, to change the fluid.
Here is a couple of articles that tell you a little about how it works, and how the ECM is programed to think:
http://www.motor.com/article.asp?article_ID=1039http://forum.efilive.com/showthread.php?4305-4L80E-Reference-Material