Those will go too. Every seat in the place will be sold and occupied. In addition to the SRO.
I'm betting an all time Nationals Ballpark attendance record for the NLDS Game 1. There. I said it.
The record to beat at Nationals Park: 44,685 on Saturday 20th August 2011 vs Phillies.
The record to beat overall: 45,157 at RFK on Sunday 18th June 2006 vs Yankees.