I was up at Fiddletown with Rashad on Friday night. The dew was horrendous, the seeing so-so and the temperature got down to around 33 degrees with frost on various accessories that were wet from the dew.
I was working on my Herschel II list of objects in Monoceros so I did most of my serious observing from 10:00 at night until 3:30 in the morning. Thanks to my Kendrick dew system and an Orion Flex sheild on the front end of the Starsplitter I was able to do useful observing (Rashad, having neither was foreced to turn in around 9:00!).
I still had some problems with fogging when I put put my eye up to the eyepiece due to warm miost air around my face ( maybe exacerbated by my wearing my "Fargo" hat) and especially when hauling cold higher power eyepieces and OIII/UHC filters out of my eyepiece box. Bummer, when a lot of the objects I was searching for were reflection nebulas!
I've ordered some Parkers Perfect anti-fogging solution (recently reviewed in Sky & Tel) to put on my eyepieces and reading glasses (another major problem). In retrospect, some kind of eyebox warmer (maybe a second Kendrick anti-dew system) would also be useful.