Ok, another lesson: that's not simply "dry ale yeast," that's Safale US-05. Every strain has its own properties, dry ale yeast is not universal, so you need to be specific about what strain you're using to get the best info. If you we're using Nottingham, for instance, which is another strain of dry ale yeast, the temps you're seeing might be on the low end of OK. But for US-05, you're just a few degrees too cool.
Now, if you can get the fermenter somewhere about 10 degrees warmer, just long enough for the fermentation to start off, you should be ok to move it back out to the garage again (remember fermentation creates 5-10 degrees of heat, which should move this beer right into the low range for this yeast, at least while the yeast is really active). But you'll want to watch for the ferment to slow down again - at that point you'll want to bring it back again to someplace about 10 degrees warmer to keep the yeast active so they can finish up completely.