It should be fine since you have pretty much everything going for it that you can. I have spoken with someone at my LHBS about this, and their opinion is to get that new wort directly onto the cake. The thought behind it being that as you siphon the beer out of the primary, you are drawing air and possible contaminants into the carboy. If this were then left at room temp any bacteria that snuck in could start eating the dextrins that the yeast left behind and start building up their numbers. Since it's been sitting at 55F since then, I'd think that nobody in there had much of a chance to eat anything.
In the future I would try to brew on racking/bottling day. Sitting on the yeast those extra two weeks would do the beer good and you wouldn't have a cake sitting around, pleading to have some delicious wort dumped on it.