Hello kwx,

Some great moments you showed us, thanks.
Your trip sounds amazing, how much time are you planning to spend? I dont know if you know but you need special permits for Tibet and they are pricey buy well worth it.

As for your question, well that little bike you posted will probably not make it out of Shanxi but it might take you all the way back to France....never know. I wouldnt risk the stress ;)
The RX3 is a good bike and would do ok for the entire trip i think but its nor really an offroad bike. Look up some reviews here and you will get some more info.
On the cheaper side there is Jialing jh150gy-3 like here. A lot people rode them around China and they made it so it would seem that they are good, but its only 150cc.
There is Shineray X2 here is good. It has both good and bad reviews but mostly good and Id say its the best Chinese enduro bike. You could probably get bigger tank and softer sit for it n taobao.
The 3rd one is Shineray X5 here bigger, more comfy with big tank and high clearance, pretty decent for this kind of trip but more expensive.

There is also a fleet of cheap and reliable hondas, suzukis and yamahas but you cant find a real offroad bike among them

hope this helps