I think coldness has alot to do with how much alcohol you've consumed, if you have kids or not, and where you are camping. If you are finding it too cold, leave the kids with Grandma, buy a few extra brewski's, and plan to camp in North Qld.
I have always found that those micro-fibre blankets are just that bit warmer than most, one over and one under can make a big difference. Put some flanno sheets on the bed and take an extra blanket or two. If you are still cold, plan to do some exercise before bed and you should be fine.
Kit_e