The parts arrived and I immediately set to work making the first node. This log will highlight the construction process.
I had a beautiful stroke of luck. Those solar keychain lights from the 100 yen shop(dollar store), from which I love to harvest 5V solar panels and rechargeable coin cells, just happen to provide the perfect enclosure for this project. Here's what the keychains look like new.
That square button on the back is exactly the size of an 8 pin DIP socket and the three LED holes are just right for sticking the IR receiver, LED and light sensor through. And to top everything off, when all the components are removed from the green pcb except for that sophisticated charge controller(a diode), a piece of protoboard of just the right size fits snugly in place. Also notice the small 100uF cap next to the battery.
Then I just snap it back together and it's done. You can see the ATtiny85 sticking out of the button hole on the back along with the thermistor. This allows me to pop the chip out for programming without even opening anything. This is all just too convenient.
And since I obviously had to decide on resistor and capacitor values, I've updated the schematic to include more info. (EDIT: I had the sensor names backwards)