Well, you would leave ketosis. Your body would switch back to a carb burning process instead of a fat burning.
You would gain several pounds, because carbs make your body retain water. At this point it would be just water, but since you've left ketosis you might feel dragging until you get the fat burning engine going again.
I've found that eating carbs again makes me sick to my stomach. You could have even more dramatic digestive protests if you suddenly add those many carbs again.
For me, it's just not worth it. Who remembers what it tasted like the next day? When you are dealing with bloating, naseau, and wacky blood sugars?
Trust me, whatever it is, it will be made again in the future.