I'm working on a 12 square blanket. My first attempt at knitting so large in one piece. So far so good. I'm just working off 3 patterns at the same time. Row by row by row. You'll most likely have to make a few moderations to the patterns you want to use though to make them fit. Mine is a little easier because I'm just doing "things" inside each square so I'm really just using stockinette with varying borders and embossed design type stuff.
Marlene / DetroitKnitter