I am not an expert. But I do know that glucose is your body's preferred fuel. Glucose is most easily obtained by breaking down carbohydrates in the digestive tract. Then it can come from stored gyclogen most likely found in muscle tissue. Once those reserves are gone the body turns to fat to burn for fuel.

Your body is going to take the path of least resistance and burn the fuel that's most readily accessible. In your example, that would most likely be the the carbs still found in your digestive tract. So, in theory, yes. You can help "undo" that one off extra consumption through exercise or fasting.

I would not bother worrying about going over on the occasional day. If you find this is happening regularly i.e. several times a week, I would seriously consider increasing my fat intake first and then protein to get me through to the next meal and not having extra carbs.

Any exercise/movement is good for making one feel uplifted but I have never seen exercise as a means to weight loss. If one feels good then good eating improves, weight loss is then a bi-product of good feelings.

In my experience as a diabetic I find there is a direct relationship between carbs, exercise and blood glucose. I find the same relationship with weight loss. If I exercise regularly I may eat a little more but not nearly as much as the exercise burns off. Thus I find it easier to lose weight in periods of regular exercise. If my activity levels drop then I may eat less and have good blood glucose levels but my rate of weight loss slows significantly. For me I find that if I workout 4x per week with a blend of aerobic and strength training combined with my Keto diet under 20 g net carbs per day and an extra 200 calories per I’ll lose weight at twice the rate vs just eating less calories. I go thru stretches where it is difficult to find time for exercise and this is consistently what I observe. Blood Glucose is similar though I find net carbs is more directly related but exercise is still a factor. My speculation is that exercise would help to offset a higher than desired carb day but my sense is that it isn’t 1:1 relationship with calories. Every little bit helps and maybe if burned 2-3x calories for extra carbs you’d offset the extra. I have no way to know if this is true I’m just speculating based on measuring my own caloric and carb intake compared with BG measurements and what I see on the scale. YMMV...