Good idea on the multiple tinders, Raptor. I'll see if I can order some tinder-quik when I get my sparklite.
I will have fleece layered under drytop/drypants during the colder months. It may not be enough during a cold, night though - especially since a night on the riverbank will probably start with a swim! I'll look into grabbing a couple heetsheets bivy bags.
I'll look into the Esbit stove, too. I'm not sure if I'll have enough room for stove and a pot, but I may head down to REI with my drybag and see how well it fits! Does anyone know how well stainless steel water bottles hold up to direct heat? I wouldn't expect any issues, but you never know....
I'm not sure what I'll end up doing for food. Since we're unlikely to be out for more than a day or two before SAR shows up, it isn't really essential. I hadn't thought about its advantages for keeping warm though. I'll see if I can get some granola bars or quality protein in my drybag. The biggest issue will be finding food that will survive the temperature swings - it gets pretty warm here in the summer.