Here are the pictures I promised of how I covered it. We were in the low 60s last week so I just finished covering it. If I lose it I lose it. It wasn't a big mat like yours. Just a smallish plant. Yours was really nice though!
The Colocasia Gigantea Thailand Giant Strain that I'm leaving out next to the Musa Yunnanense.
Musa Yunnanense after a low of 25 degrees.
The whole thing. I covered it with more straw and leaves to cover the entire plants.
And burlap over the top, then plastic to keep mositure out. That should also help keep it warmer.
The ones next to the house got a very similar covering, minus the burlap.
Eric