That sounds like teeth Kate, is it possible? The not eating and night discomfort is classic teeth for us. And the mood swings, very teeth.
If it is teeth and he had a short night, I might give him 45 mins, but then again with Finn it's always best to stick with the current routine, even if it means we have a grumpy so and so on our hands. He's not big on change and would bless us with a long PM nap, just be careful with that middle A time because you don't want him OT.