Anyone have additional thoughts on reducing / eliminating frost damage?

Our vineyard is at about 2800' here in the Sierra Foothills. April
frosts, soon afer budbreak, are an annual anxiety. Last night was a
cold one, and we've got some notable frost damage this morning.

Tonight looks to be another cold one, probably worse (no wind), so
we're irrigating heavy today, trying to get the soil around the vines
as saturated as possible in an atempt to try and change the soil heat
radiation profile as much as possible.

Anyone use any additional frost protection strategies? Sprinklers and
fans are not possible for us jst now ($).