Byron,
Do you have an extra section of garden hose? And a way to seal the ends such as several unused spray heads? Fill the hose with water and cap the ends. (Cap one end, fill hose and then cap the other end.) Lay along side the plants. It will provide additional warmth during the day. I have done this to get young plants up and growing in the spring.

Time for some floating row cover plus water containers. If the weather has been that bad, I might even suggest clear or slightly opaque "awnings" or "umbrellas" over the plants for additional heat and reduced wetting with cold rains.

When I was gardening in the high desert with lots of growing degree days but cold nights I switched from wall-o-water to 2 liter bottles. I found the bottles easier to handle and were free from the 7-11 dumpster.