if you have stamina of long drive then its doable, have to leave early in morning on days where travel time is more than 7-8 hours, there are unexpected incidents on road, landsliding is normal and you can stuck in traffic for couple of hours, so keep in your schedule 3-4 hrs extra.
from multan to shogran, its doable as now you will use motorway till manshera, else crossing abbotabad in day time takes 3-4 hours.
from naran to karimabad, leave early, max by 7 am you leave naran. as sun rise rush increase on babusar pass, and in rush time it takes 3-4 hrs to cross babusar pass, other than that its matter of 10 min. same is problem on every stream/glacier crossing. in morning, no rush and you go, but in day time every crossing take 10-20 min extra.
stay in larimabad, nagar bahi gave good advise, as karimabad is a normal russhy city. full of tourist/traffic.
passu to batakundi, same approach leave as early as possible. its better to leave early and reach early on destination instead of sitting road side for hours and hours. we were left hunza by 9 and plan was to reach batakundi, but on mid of way road was blocked for some cycle race and we waited 3 hrs on roadside. due to which we reach chilas by sunset and have to stay there for a night.
and leaving batakundi after 9 means you will reach isb late night. it took 4-5 hrs to reach balakot and then 3 hrs traffic jam in abbotabad. . while it takes 2 hrs if leave early from naran.
nagar1 is best guide for GB areas. we planned out trip as per his advise,which we followed except timing schedule and keep on getting stuck on roads.