There is another variable which effects one's perception of temperature aboard. I continue to experiment however the basic conclusion is:
Drink full bottle of red (or equivalent) = It's too hot. Kick off duvet, blanket or whatever.
Drink no alcohol = It's too cold. Tuck duvet, blanket in tighter. Add sweater.
Somewhere in between there is the right balance for each individual; but each individual will of course be different...