Making a temporary walkway
Your local home center(Lowes/HomeDepot) should have 12inch x 12inch concrete patio blocks  for about $2 each, even less if you find some with chipped corners. Since it is a short term project I would just lay them on the dirt following the original line. The blocks should spread the load enough that they won't sink too deep into the mud. When it's time to get your new walkway, just pick them up.