If the fluid drains out, it would slip and then go into neutral as there is no ATF to provide pressure to the clutch packs. IMO, the oil pan and trans pan is tuck up quite well. I think the cooler lines should be fine as they are routed between the tranmission and radiator. I have driven into deep grooves and washboard but most of the beating was on the exhaust and sub frame.

What you need to do is switch out that Tomtom for a Garmin. J/K

 

If the transmission last fluid and can't function and you stopped and had the car towed, then there is a good chance everything is will still work ok when you fix the leak and refill.

You can also clean the pan this time, and then drop the pan say after 7500 miles and check for debris.

 

i would think you would burn out the clutch packs inside if they tranny ran dry. i thought the oil pan hangs lower than the trans pan so that would take an impact first.

 

I think the only way to make a hole in trans pan is to be very unfortunate and hit a rocky sharp bump with it as normally the sub-frame and exhaust (as mentioned above) take all the scratching first, then the oil pan and lastly the trans pan ... so your car would be pretty much done before the trans pan got ripped ... unless you were VERY unlucky, just saying

EDIT:
you should go to your GPS navigation/map settings and select Avoidance for non-asphalt/rough roads (or off roads or whatever it's called) ... at least I have that in my Garmin
also set that navigation for fastest routes, not the shortest ones shortest doesn't mean quickest hehe