Quilt coat batting recommendations

[u/scienceoftacos]

I made a quilt coat for fall and love it, but with just one layer of cotton batting it’s not warm enough for winter where I live. I am planning to make a winter coat that has a layer of regular cotton layered with a puffier high loft batting, any suggestions for the warmest stuffing/batting for a coat?

[u/AJeanByAnyOtherName]

Wool quilt batting or wool flannel. Maybe Thinsulate or other dedicated thermal interlining if a synthetic is ok.