You should be OK, but a 40 qt would be a lot less hassle. If you can contemplate brewing in aluminum, you could probably pick up a 10 gallon pot for pretty cheap. I got one for around $36 bucks or so.
I use that, along with the 30 qt pot from a turkey fryer for brew days. I mash (BIAB) in the smaller pot, in order to minimize headspace during the rest period, and then dunk sparge and boil in the 10 gallon pot. It actually works pretty slick.
Note: I have tried boiling a 5-gallon batch in the 30 qt pot, and I had to fight tooth-and-nail to keep from boiling over. The extra 2 qts might help, but I would think they won't make a huge difference.