425.
Just got back from 375 miles in 2 1/2 days in Sayner / Boulder Junction / Phelps / LOL / Presque Isle area. Found a lot more good and very good riding than expected, but they need more snow.
I agree with others, it is not at all about the total miles, it is about the quality. Saturday night return trip after dinner from Boulder to Sayner was 58 miles (the direct route is about 20). 53 miles had just been groomed, and we passed 3 groomers on this trip. Perfect moonlit night, nice easy cruising speed, just about as close to a "zen" time on a sled as I have had.