I agree I would leave your stepping stones in place. I sprinkle my compost in the Spring because we have heavy rains and I like it to wash into the soil in the Spring. We do not usually get a lot of snow. Except last year was a monster. They are saying we are going to have another bad winter. I do not know if it is cold or snow bad.
When I plant late I put a stone on top of the roots of the plants because we get a lot of heaving with the freeze and thaw. That kills my plants more than the freezing.