I want to visit a friend in China and the maximum time I have for travel is 34 days. I want to buy the tickets now for December -January. My passport will be here in a few weeks and then I can get my Visa. But what if my Visa only gets approved for 30 days? I'll be in rural China (North of Chengdu, in Gansu) and I most likely wont be near an office to get it extended while in China. What is the best method at this point?

Shorten my trip to 30 days 29 night? Do my normal trip of 34 days 33 nights? or just wait til I get a visa to buy place tickets, and hope the price doesn't increase?

Thanks for your help