Pumpkin Ale No Signs of Fermentation

I brewed Yuri's Thunderstruck Pumpkin ale last Friday and now find myself in an awkward situation. I had to leave town on Saturday so I assumed it would be alright and fermentation would take place. When I woke up saturday and checked for activity before I left, the airlock was not moving and the temp was up around 76. I decided to put the brew in a water bath to cool it down some hoping that may help. It had been in the 70s for the past week in GA so I figured it would be alright to sit there, well sure enough the temperature dropped back down to near freezing and when I came home the fermometer read 56. I shined a flashlight on the top of the primary (bucket - and I have not opened it yet) and it seems that there is no krausen developing. By now the other beers I have brewed already had a few thick inches. My two main questions are, could the yeast have become dormant and then got swallowed up in the pumpking and are now in the bottom of the bucket or is it possible that the higher tempuratures at the beginning didn't help with the fermentation process. I'm using US-04 and I rehydrated the yeast before I pitched, pitched at 74 F. Any help would be great, I'm guessing I need to wait a few more days then check the gravity and maybe repitch.

Could just be the low temps, but did you use canned pumpkin? If so, were there preservatives in it?

I used canned pumpkin, the brand that yuri recommended, can't remember which one but it was 100% pumpking but I'm not sure about the preservatives.

Edit - Brand is Libby's