Me too, in covered boxes under the house. At the moment, in Brisbane the temps are steady around 16-19C so I'm trying to get stocks up.
Just don't fluctuate temps, ie. put in fridge then take out, then put back in again. Keep it steady. In summer I try to squeeze as many in the fermenting fridge. I pretty much brew ales all year round, and can fit a couple dozen longnecks in the fridge around the fermenters.
With bulk priming, the most important advice I can give is stir constantly, but carefully so that all the priming sugar dissolves properly into the entire batch. (yes I boil on stove beforehand).
When I whirlpool, I stir at the same time with a plastic paint stirrer until the fermenter is fully drained. You don't want to run the risk of having a couple of bottles getting all the priming sugar and exploding, and then having the rest of your beers dead flat. It's heartbreaking, trust me!