Painiacs, the slipper pattern is Simplicity 2278. I left off the strap, and cut the pattern up higher, closer to the ankle. I then widened it, since I have very wide feet. I ended up using a gift box and traced the outline of my foot to be sure the bottom of my foot fit the bottom of the slipper. Had to widen it too.
I've cut out two pair of pajama bottoms today, and a couple more pair of slippers are on my list too.