This past Friday night I went with the local scout trip on an overnight campout. The topic was Wilderness Survival - so we were supposed to build shelter (no tents).
We left in a rainstorm. We drove in a rainstorm. We set up camp in a rainstorm. It rained until midnight. After that, it was beautiful. The coldest it got was about 40 degrees.
Just a couple of observations... and none will be earth shattering.
You need gear to stay dry. Three scouts ended up sleeping in a car. Their stuff got wet - they were done.
You can get by on very little. One scout slept under a tarp and in a couple layers of Under Armour and some trash bags. He did OK.
My setup was a blue tarp, bivy bag, and sleeping bag, on the ground. I was dry.
As far as clothing... I had a long Gore-Tex jacket. I was fine from head to knees. Below that, I was OK because it wasn't colder. What I'd really like to have is a good hat with a brim, a long duster type jacket, and some waterproof shoes/boots. With that and a good pair of gloves, I could spend a long time in wet 20 - 40 degree weather and be OK - I think.
The next day, under blue sky, we did orienteering, signaling (you'd be amazed how well a 2" - 3" mirror will signal at 1/2 mile), fire starting, and the like.
I think we have the best scoutmaster in the world.