Travel Yungang Grottoes, Hanging monastery (Xuangkong temple) and Visit temples in Wutaishan

Dear sir,
Could you please help me suggest place to visit in Datong. My itinerary is flight from guangzhou to DT in the evening. And i have 3days (Dec.28,29,30)to travel in Yungang Grottoes, Hanging monastery (Xuangkong temple) and Visit temples in Wutaishan. Is it enough to travel all location in3 days? The last day (Dec.30)I have flight on 7pm. back to guangzhou.

On Dec. , is it difficult for the old man (65 years old) climb up to the Hanging Monastery? And elevator in there?
Do you have any suggestion for other interesting place?

Can i stay in the same hotel for the whole trip? I plan to stay at Holiday Inn ( DT City).

Thank you very much.