We use a piece of Reflectix (available at Home Depot and Lowes) insulation cut to fit the pad and held on by straps to immediately radiate heat back to you for winter camping. I use a bag, but use it as a quilt thrown over us 90% of the time. When set up on snow and ice we also use a SOL e-blanket as a tent floor. I think the Reflectix would solve your problem very easily.
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Charlie