Having some snow on trees and ground, even if it is not that heavy like the one we had last night, is not bad at all. Having a layer of dry snow on the ground should provide good insulation for soil and roots against the expected low temperatures we will face tonight and tomorrow morning. Also, large limbs that are still loaded with snow should get some protection. Using sprinklers will worsen the situation as wet snow works as a good thermal conductor and will transfer these freezing temperatures to roots much faster than dry snow.