After just having recieved my new SMD Gatewood Cape, and setting it up in the back field to seam seal it, I decided to use the opportunity to check out if my Montbell Thermal Sheet could suffice for its rating without any additional help.
The Thermal Sheet is rated in the advertisements to be good down to 50F. I have read anecdotes that it had an "optimistic" rating. I had a weather forecast yesterday that the temps would be in the low 50s at night. So, I put my "space" mylar groundsheet down, inflated my Klymit X-Lite pad, and rolled out my Montbell thermal sheet inside the Gatewood Cape. I also had an inflatable travel pillow of the horseshoe style, and I inflated that too. The fleecy fabric cover was removed from the pillow for weight reduction previously.
The Gatewood Cape was set up and re-tensioned by nightfall. BTW, I waited until about an hour after nightfall to get into the tarp, because I didn't have the bug net inner tent inside the GC. When I got in, there were essentially no bugs around. The set up was intentionally in the most condensation prone location I could find, so that I could see how the GC did for condensation when the temps dropped below dew point. It was an open grassy field with no overhead leaf coverage, and a clear crisp night, and we have had a lot of rain lately, and my field is low-lying.
I did not have a full footprint groundsheet, so the entire vestibule ground area was open under the tarp, with exposed grass for moisture to be available from the ground.
I went to sleep in the bag with just the clothes that I had worn all day, as a typical "control" setting. No special baselayers or anything. Just a pair of cotton cargo shorts and a cotton T-shirt. No socks. I did bring a women's shower cap outside with me, because the Thermal Sheet does not have any hood. It stops at the shoulders. I ended up using the shower cap to help keep my bald head warm, and it worked.
At the time I turned-in at about 10pm last night, there was already a light coat of condensation on the tarp. The pitch was tight, and nothing dripped on me all night. There was almost no wind at all, for the entire night. Very still.
So, I woke up at sunrise this morning, and it was 52 degrees F. I felt a bit chilly, but it wasn't horrible. No shivering. I think this MB Thermal Sheet is fairly rated. I am a cold sleeper, and I always like to be a little bit on the warm side. So for me, this is good performance because I get cold easier than many of you out there reading this. I wouldn't want to take this Thermal Sheet any lower in temps without some sort of heavier base layer on, or using some other form of help to keep warmer.
But I wasn't "freezing cold".
It was a good kind of chilly, in a "crisp morning" kind of way, and if I had a campfire outside or something, it would have been perfect to brew a cup of coffee and sit by the campfire to warm up and enjoy the early morning time before breaking camp.
BTW, my impression of the Gatewood Cape as a shelter was VERY good. I am accustomed to using a 5x8 flat tarp in half-mid config, and this thing was like a palace in comparison. It's basically a half-mid with a very large beak/vestibule, and it has what I consider to be full-coverage for all intents and purposes. I won't get wet in this thing, but I got wet plenty under the 5x8 tarp. The condensation with the hood tied shut and pitched about 6" off the ground was minimal. There was a light coating of condensation all over it, but nothing was dripping off. I was dry, and even though my down bag foot touched the wall a few times, it didn't wet the bag in any noticeable way.
Very easy to pitch too. Plenty of room. Can sit up. Door works good and is very nice, and can be rolled and tied open. It pitches tight, and is weathertight and stable and roomy.
I am very pleased with my purchase of the Gatewood Cape.
Regarding the Klymit Inertia X-Lite pad, this was my first night with it.
I inflated it fairly full, but I left it sort of squishy. It's not a thick pad, but it supported my 225 pounds off the ground, and if I hit the ground with my hips when side-sleeping, I didn't notice it. It was surprisingly comfortable. I'm 5'10, and I fit the pad properly, so this may have something to do with my successful use of it. But I liked it, and it was comfortable on my back and on both sides during the night, and I had no aches or pains at all when I got up. This gets a big "thumbs up" from me.
I will say that the cheap travel pillow was a God-send. I like to have my head supported, and without that travel pillow, I would not have been happy.
Overall, the gear all worked as intended, and my night out in 52 degree weather was successful and comfortable, but near the lower limits of what this Montbell Thermal Sheet can do on its own. I have no doubt that it could go into the 40s with some good warm baselayers on, to help it out. And a good warm hat or hood.
The temp didn't hit exactly 50F to test the rating, but it got very close to that, and I got a feel for what it can do near its advertised limit, and I think it's rated accurately.
Gatewood Cape = 11 ounces
Montbell Thermal Sheet Sleeping Bag = 13 ounces
Klymit X-Lite pad = 6.5 ounces
Mylar Space Groundsheet(trimmed) = 1.5 ounces
Total weight of overnight gear = 32 ounces(2 pounds total)
Add in my GG RikSak pack at 2.3 ounces, and you have my Base Weight at 34.5 ounces.
Just over 2 pounds Base Weight.