Most of my quilts either go to Australia, California or South Africa..... all have hot weather, and cold weather.
Since I am either sending them with someone on the plane, or I have to mail them. I have used flannel sheets. So far no one has complained, and trust me, if they didn't like it, I'd hear about it.
I live in the north and for anyone Canadian I use either recycled fleece or a 80/20 mix. So far no complaints on those either.
I make quilts with what I can afford, or have on hand, and if they don't like it.... well, to bad!