Well, my question is when he says "heavier", does he really mean more weight, or does he mean warmer? Because your answer to this question is dependent on what he means. My husband likes heavy quilts and blankets, meaning he likes the weight. So, if my husband said "heavier" to me, I'd use more flannel. I made a 3-layer flannel quilt and it is HEAVY. However, if my husband said "warmer", then I'd switch to wool batting, which is NOT what I would consider a heavy batting. If your husband wants both, then you can double up on the batting. I know a lot of for-show quilters who use W&N 80/20 with a layer of wool on top, because the wool shows their quilting beautifully.