Assalam-o-Alakum Ahmed Brother,
I know its too late to answer but still it will be nice to have a chat with you.
I was on a tour to Swat, came back and got busy as usual, just saw your post today, my apology for being late.
I think it may take 8-9 hours from Peshawar to Dir. If you start at night and reach Dir in the early hours of day, then you can reach Jandrai as it is about 5 hours jeep journey from Dir to Jandrai.
If you have already done it, I will be waiting for the story of your stay at Kumrat..