Well, I'm all for breaks when you get to plateaus. But not all out breaks, because like you said it is so easy to slip into our old ways. 3 weeks is a while with no budge, so I'd probably take at least 2-3 days and go ahead and eat at maintenance. Don't try for a deficit, but still watch what you are eating. Two days of chocolate cake and lasagna is not what we are looking for!

Just allow yourself to eat more, maybe a treat or so, but keep control. Maybe take a break from your intense workouts and just walk. Still making healthy choices, just with less intensity. That way your body can take some time to adjust to its new size. This has always helped me when I get stuck.