Diacetyl rest or longer primary?

I have a slightly modded version of Ed's Haus Ale in primary right now. Through the most active few days it was fermenting at 64*F, but as activity decreased it has dropped to 61*F and may drop further because the basement closet where I ferment is a pretty cool spot (usually around 55 ambient, but warming up a little as outside temps increase). My question is this: do I need to worry about Nottingham yeast producing diacetyl at these temps, and would you raise it for a few days diacetyl rest or just let it mellow a bit longer?

I know 64 is close to what people often use for a rest, but 59 is a bit low and I am not used to fermenting this cool. I therefore don't know if I should expect diacetyl from cooler temps later in primary and Danstar's data sheet for Notty doesn't even mention diacetyl.

I would raise the temp up to ~ 65-68 for a few days to let the yeast finish up strong and clean up after itself. The bulk of the ferm. is over so you don't need to worry about any esters added from the raised temps. After a few days at warmer temps. you can chill it if you want to flocc, out some yeast. Personally, if it were mine, I'd let it sit at ~ 65-68 (10-14 days) until the night before bottling/kegging and then cold crash it overnight.

Thanks. That's the way I was leaning too, but wasn't totally sure. Not going to cold crash though. I bottle, and I've found that bottle conditioning takes forever after cold crashing.