I don't like heavy quilts because they are difficult for me to sling around, plus they are heavy to wash. Also, I think double-batting would be difficult to quilt on a domestic machine. (I have seen it done on longarms.)
I think warmth is easier to achieve with layering. My solution would be to buy a cotton blanket and double-layer the blanket under the quilt on your husband's side.
Wool batting would be the warmest batting for the quilt. Maybe save the polydown for another quilt? Connecting Threads has the Hobbs wool still on sale for $39.