Yes, the highway is open. It takes from Xishan Area (e.g. Guangfu Lu) to Hilton 1 hour door to door by car.

Hop on the highway towards Banna, then take the Chengjiang exit it's after an ascent in a slight right turn, so dont miss it. Then all the way to Chengjiang (around 40 minutes). Drive into town and then right to the lake. Near the lake is an intersectiopn where you turn to the east to go towards Angsana or Hilton. Highway toll fee is around 24 RMB per way.

With the YELLOW paper and your photo on it, it's no problem at all to travel anywhere. I was just in September on a 3 week trip with various flights. I was even a few years ago at Karakul Lake which is special zone, requires an additional permit to cross the checkpoint. All no problem at all.

The only morons who give me trouble each time is the Bank of China. They ALWAYS claim it's not possible to use the yellow paper as passport replacement, but in fact it is. So if you need to go to the bank, just insist and refuse to leave until it's resolved. They may need to call Beijing or else to double check, but you can do all your money affairs on the bank with that paper too. Just don't let those plonkers at the bank tell you otherwise.

A few months ago, I walked in and they gave me a "temporary" card for the single purchase. Upon the next visit, I filled in a paper, gave them a copy of my passport and they made me a card. So no problem at all to get a card.