Trains on 5th May 2017 Golden Week

Hi,

Wondering if any one has ever travelled during mid of golden week.

I am landing in Narita on the 5th of May at around 4pm. My initial plan was to head straight to Nagano on the same night. But seeing that it's golden week, is there any chance that i would not be able to get any seats from Narita to Nagano?

Since it is in the very middle of the Golden Week, I would not expect it to be too busy. The travel rush is at the beginning and end of the Golden Week (especially May 3, 6 and 7):
http://www.japan-guide.com/e/e2282.html