Xian During Chinese New Year 2018

We are planning to visit XA from Shanghai. The plan is to:
Take the high speed rail on 1st March from Shanghai and arrive same day.
1st March is still within the lunar new year period. Will the rail tickets be hard to get and will the crowd be massive?
Also, we will be in XA from 1st to 7th March. 2nd March is the 15th day of the lunar month. Will the traffic (rail, bus, etc) be very congested? Will the usual sights like Huashan, terracota warrior etc, still be open?

Many thanks in advance for any advice and help!