Solo'd nightfall on my 28 lock, with icebreaker everything up to final boss is pretty easy - snipe from a far distance, nothing ever shot at me.
I'm sure its been mentioned here but if you want to cheese the last boss solo, take a weapon that has armor penetration on it. I used Final Death, a sniper rifle and swapped to Ice Breaker to regen ammo.
You can clear all the adds before the boss from the entrance ledge, just snipe from there and run out to clear the stragglers. Practice getting under the little ramp room, if you cower under the actual ramp portion nothing can hit you at all. With an armor piercing gun you can shoot at the boss who is stomping around above you, although its hard to really see much especially when a bunch of mobs start stacking. It took me a good 30 minutes to kill him, but didn't really require any effort just swapping weapons every 60 seconds and firing off a bunch of shots at pixels that looked like they were him.