Well I found the PERFECT solution for this. I mean, it's really truly brilliant. And I really wish I could take credit for it, but I can't. I found The Jammie Fixer Tutorial over at No Big Dill and I knew I had to try it. I went to Joann's and they had rib knit on sale so I grabbed half a yard for just over $3. And the amount of material I used for one pair of jammies was so small I could easily fix 10 more pairs with what I have left. So not only is this a great fix, but it's inexpensive and easy, too.
Go check out the tutorial at No Big Dill for more details, but here are some photos of the process that I took.
I cut the rib knit, folded in half and sewed a straight line to make a tube.
Then I folded it with the seam inside (wrong sides together), slipped it over the foot right sides together and pinned.
A comparison of before and after.
And here's my little monkey in his jammies!
The flash always makes him blink.