What to do?  I sat at the dining table and played a couple of games of solitaire while I reasoned it out.  And suddenly I knew just what to do!  There was a load of unfolded laundry in the living room.  (Yes, my washer and dryer are in the living room!  Who builds a house like that?  One of these days I would like to know why someone thought this was a clever idea because it is just Not.)  Anyway, a clean pillowslip would be the perfect thing!  It would keep the bread fresh without creating a vapor lock, and it would fit.  So that's just what I did.  Looks a little funny sitting on the kitchen counter but that's okay.  If I continue making baguettes (and I hope I will), I'll simply stitch up a cute little cotton storage bag for the loaves.  Super-simple.
Check out the recipe on the King Arthur Flour website:  Baguettes.