Niv, I would go out at 3am and rug up with some blankets.
I think I'll be taking a couple of hot water bottles with me
Which reminds, I better go clean my banana lounge up!
All the best for tonight Niv- let us know how you go.
P.S. don't forget to take a notebook and pen and write down how many you observe as they come thru & your session time. I don't know if there's an easier way, but I keep track of them by doing that haystack thingy, you know with the 4 lines going one way and the fifth big line crossing them, lol.