One thing you could do is use your decorative stitches to sew the two layers together in places to give it a little more interest if you wanted to.

In your shoes, I would just go buy a second hand white or light colored sheet and use it as batting so that you have some definition of your quilting, and not roast your poor DH. I live in North Central Oregon, where winters can be very cold, and electricity goes out at least once a year due to storms, but I sleep with nothing over me because I can't cool myself when asleep. Just me and my cotton knit Jammie's and most nights I am still too warm, even sleeping in front of a big fan, with the house temp set at 68!

I plan to make some quilts with only flannel for batting.

I live in Houston and I've used just cheap flannel from Joann for the middle layer in quilts and garments. It's just not cold enough here to use many quilts with batting.

I have two quilts with just flannel sheets for backing. Dh loves them. Quilting doesn't show like when you have batting.I

What about using a layer of flannel for more body and a tiny bit of warmth? I think it would quilt better with the third layer.

I saw some in a museum that had no batting. The stitches were teeny tiny and they were gorgeous. I guess if they could do it 100 years ago there is no reason you can't now.

Of course you can quilt with no batting. It won't have the definition of a quilt. But, it will suit his needs. It will be more like having two sheets on the bed instead of one. I'd stitch it. I don't really like tied quilts but some people do. It might work out fine you.

Good for you! Pleasing the hubby is the main focus!
I know I am in the minority, but the piecing is more important than the quilting anyway.

I use flannel, preshrunk,