If your aim is to be certified at 1000 miles, finish your best estimated 1000 mile ride in a city with plenty of receipt options, obtain your 1000 mile receipt and end witness. Go 1 mile further and repeat. Repeat again multiple times until you get bored or run out of time. Send in your 1st set for verification. If its refused, you will be told the mileage. Using this as your guide, send in the appropriate set to get your 1000 mile verification. If I was to plan this I would use the minimum number of stops to get to my estimated 1000 miles to allow for the messing about at the end.