You should be doing a carb up every week and so long as you follow the basic guidelines you shouldn't have any spillover.
First never use the word "binge" or "free" day. Most people use these terms lightly assuming one won't overdo it, but of course there are those who will take those terms literally and screw up all that they've lost during the week.
During this "binge" you must keep fat low, protein moderate and carbs high. You can't binge on high fat and high carbs or else you're going to have definite fat gain. Thus chinese food is probably not a good choice as a lot of it is fried and full of fat. If you want to stick to noodles and such that's fine but stay away from crap like sweet and sour, all the pork products and anything that is obviously fried.
If you want to really splurge then enjoy higher carb, lower fat goodies like ice cream, cake and candy. Just make sure they aren't the high fat variety. Pancakes and syrup for breakfast is a great choice, just skip the eggs and bacon or sausage. Pizza can be good if you make it yourself with low or non fat cheese, etc...
Being in a ketogenic state for 3 weeks I don't see how you would want to eat anything with fat anyways. Enjoy what you can't have during the week and stay away from the fat. You will get enough without even trying believe me.