take a cardboard box and put a heating pad in it. Tuck it beside your chair and the little thing should want to cuddle down into that box instead of awkwardly perched on your legs. you can move the heating pad to the arm of the chair or off the chair. Cover it with a towel or something so it wont get to hot, just leave it on low, and the kitty will love it. Cats need trade offs. If you take away, you must giveth a trade. I am sure kitty just wants to be next to you (have you seen them sleep in pig piles as kittens?) and doesnt mind sharing your chair.

Lily my kitty would sleep wrapped around my legs at night, and it made me crazy. Then one day I pulled out a heated throw blanket for my angry back and when I got hot, I threw it on the floor in the middle of the night. it was her blanket ever since. She likes to be with me, but now she isnt on me.