Think of a thru-hike like a college class - yes you can skip a few days (like as in a zero at a hostel) or even go home for a weekend maybe, but you stay with "your class" walking with the season -not getting "held back" to continue the analogy - you'll appreciate it more that way. I do also think that a flip-flop is a legit thru hike (for someone with seasonal issues, or whatever) certainly, they leave the trail for travel so it also sort of comes down to where you draw the line ethically - but I think that taking months off (even in the same year) while surely making you a 2000 miler, doesn't really cut it as a thru-hiker. Besides, you are talking about a relatively short section - just re-hike it, you'll have fun and be happier in the end.