Its still hot here in Sydney. We've had a few cool days where I have managed to run some Einstein or Seti work. The Einstein CPU tasks take about 16 hours so I am tending to run Seti as they're somewhere between 1 and 3 hours depending on the work unit.
I purchased another 5 port USB charger which I am using to power four Raspberry Pi2's. Its an Astrotek brand with a part number of AT-UPS-008B. Provided you only use 4 out of the 5 ports its fine. I have another one running four of the Pi3's. It might actually be able to run five (it reduces power output to each port when you plug in a 5th device) but I haven't tried five.