This was one of the things my LDH requested early on, for raising his libido. I usually do, except in the dead of winter. I cannot tolerate cold. Nowadays I have an electric blanket that I keep cranked so that I can stand it.
How about a playful assertive remark to her, ala blackfoot? Something like "Tonight we're sleeping nude, so don't even bother with clothes!" and take them off of her, playfully now, if she refuses your request.
Also, you may want to point out to her that you are making a request of her, just as she surely makes requests of you that you comply with. My H seemed to have this weird idea that he was not obligated to do anything wrt sex that he didn't want to, although he certainly expected me to do things that I didn't feel like doing. It was as if there was a whole different set of relational rules when it came to sex. It took several conversations for me to get thru to him, Look, all I'm doing is requesting that you do little tiny things and, most of all, to keep an open mind.
