Even though my house is big (tall and narrow) we don't have much floor space to baste quilts either. I use my mom's full sized bed (I mostly do twin or smaller) but I have done 2 larger quilts and I put as much as I can on her bed, pin heavily, then slide and do the other part that didn't fit on the bed. I too don't know where to go do pin large quilts as I'm in the middle of a queen sized quilt. I may show up at my church and do it there if my mom's bed doesn't work to well. Good luck though!