Haven't been out to the yard yet either - way too spongy and soggy still for toddlers. Our plan is to put in a large deck at the side of the house where we could play in weather like this or clear off in winter and play without getting lost in the snow.
One thing I do for outside play is that we do it at the end of the day from after nap till hometime. That way any mud or snow goes home. I ask for waterproof spalshpants and boots and if you don't bring them not my problem. But it means all the mud and sand goes home and not back into my house.