Go out and do something fun for yourself on NYE. No wife, no son; this is your time so make the most of it. If you do have plans with your son, by all means extend an invite but don't create events just to invite her along. Ride the wave, Bunches. Enjoy it.
Me: 31, W: 29 T: 4 M: 2 Kids: 3 (SS: 7, SD: 4, D: 3) Separated, still living together: Nov 2013 Separate bedrooms: Feb 2014 W working away; kids with me: Nov 2014