It is now actually 1848 from T-1. 1850 from T-2.

That is the last chance because the last JR Pass-eligible shinkansen leaves Shinagawa for Kyoto at 2010. Any Narita Express leaving NRT after the 1848 won't get to Shinagawa until after that last train has left.

The fall-back would be to TRY for that train and if you can't make it just bite the bullet and pay cash for seats on the Nozomi shinkansen which has later departures for Kyoto. That does eat into the value of the Rail Pass, though, so you might want to rethink your 7-day activation period and make it for the LAST 7 days instead if that happens.