[Zeke]

It takes warmth to cure the oils. You can oil stain in cold weather but not freezing weather. The low day time temps are going to retard the curing. Night time temps below freezing will likely ruin the job.

When you call the company ask them if you can do a quick wash stain. Over-thinned and warmed in hot water. It's just an idea, I've never done it. We don't get down to below 40º hardly ever here. Too close to the ocean.

You could use a propane space heater in proximity to the deck but you are literally playing with fire. Probably not a good idea unless you shut down the heater before putting down the stain.

On the back rolling: what kind of stain will spray through a pump sprayer that needs back rolling? Now I can see mopping to pick up and spread any excess, but my experience does not include the use of a roller unless it is locked and skidded or dragged.