Have you camped in temps that cold before? You might be surprised how cold the upper 30s F are when you are tent camping. Depending on your sleeping bag, you may need to wear wool socks, long underwear, and a beanie just to stay warm while you sleep.
Heh. The first night of my first ever tour (across the U.S. using ACA's Northern Tier route) we camped at Kitsap Memorial Park in WA. It was my first night ever camping. It was freezing in later May. I don't remember what I wore at night, but I did have a 32 degree bag.
If I am going to be in an area where it might get nippy at night I will bring a warm pair of wool socks, a bottom base layer (I have a synthetic one and a wool one), my Rahpa top base layer and a wool hat along with the little beanie that fits under my helmet.