How Does BroadwayCon Affect Show Traffic?

I am hoping to make a trip down to NYC the same weekend of BroadwayCon (1/27-1/28). I was hoping to have fairly good luck with rush lines during this time, but will there be more people in the lines and at shows because of BroadwayCon?

Also, I noticed that this trip would fall during Broadway Week. Would I be able to get the 2 for 1 tickets at the box office once I get there, or do I have to purchase the tickets ahead of time (with fees)?

Thanks in advance!

Thank you Broadway Joe! I don't think I'll be hoping for weather this cold, but if rush lines can stay short I guess I can't complain!

I haven't been in NYC during BroadwayCon/Broadway Week before, does they typically attract a lot of people?