I was suspecting that was going to be the solution, although I was hoping to carry something a little more compact. When I used to car camp, I had a therm-a-rest base camp air mattress with an r-value of 8. And I never had any problems. But once I started backpacking and looking for compact/lightweight pads, tI started having problems. I suspect that I might have a slight circulation problem to my extremities. I had a recent pulse ox reading of 90, which is low, and I went backpacking a few weeks ago, the night time low temp was only 55 degrees and I was in a 40 degree bag. I slept fine most of the night and then close to morning, I woke up shivering and convulsing. I had to do some exercise just to function well enough to break camp and and get hiking again, so I could stay warm. In the winter, I have a zero degree bag that I use and have froze my butt off in dry clothes at only 23 degrees. But this is why I always carry insulated gloves and a hat. I should also look into some kind of down jacket and also maybe a fleece jacket.
Thanks for the advice though, Mik. I might just accept this as a fact of life and save myself some money by simply taking my closed cell pad along.