Hi and welcome! Glad you found the forum helpful!

Looks like you've done your homework and understand the difficulties of biking in china. The license thing is very lucky for you guys!!!

About crossing tibet, do you have a plan or some info that we don't know about; or are you just going to go for it and see what happens? Because there's a chance that your route from kunming to kashgar through tibet might end up looking something like this:



Also are you constrained to july for the trip? If not, april or may will likely have much less rain!