I believe your friends can actually help you with the last 20 floors, they just dont get credit til their progress is that high. But yea sit tight for the possible trust help in NNI, until then you will have to take your chances or get 2 other people. i think the smallest amount of lamps in multi lamp floors is 3, but some like same time you could possibly hit if they were close enough to each other.

Allowing us to enter solo was somethign we were asking for so they allowed it, but just hadnt come up with a way to make the whole event soloable yet (if they even do)