Fermenting zone

I just placed an IPA in the primary and i had a couple of days where the temp was down to 50 degrees which is out of the zone and has stopped fermenting. My question is after i get the temps back up will it start again?
Does it really matter how long it sits there out of the temp zone?

Depends on which yeast strain you are using to ferment the beer. I'm assuming you used an American ale strain since it's popular for IPAs. It's a hardy strain so it should start up again, but you really want to make sure the temperatures don't fall below 62F because it starts flocculating. I have heard that if the yeast is in a cold environment it might go dormant and then it can be hard to revive it, but I think your fermentation will be fine if you warm the fermenter up.
You should try some lagers, they would be perfect for your cold temperatures.