At 47F, its a little more on the cold side, but not by much. I've gotten as low as 42F and it took 2 1/2 more weeks to finish. I would go ahead and raise the temperature a bit (slowly) to around 55 for a 3-4 days and if you can take a hydrometer reading. My sake tends to be a little drier around .090 to .092. Take a sterile sample and see how sweet it tastes. I will not be quite the same as the rice solids will tend to make it seem sweeter than it is - nigori style but can give a ball park. If the bubbles are really slow, you are probably done.
Looks like you are close to the end. Letting it continue will dry out your sake, so you might want to stop it. Once pressed, you can let that settle and a little secondary fermentation will ensue. Don't wait too long as you exposed the sake when pressing. This is to let the majority of the fine lees to drop out. Pasteurizing will halt the fermentation.
Hope this helps,