I went on this route last year in July (2017). 15 days after Eid. Peak Season.
Me, wife and 4 kids ages 11 to 18. Vehicle Toyota Altis 1.6 2015 Model. Total Expenses probably 150K.
There are medical stores in Naran and Hunza for basic medicines.
Travel Details are.
DG Khan to Kallar Khar. Night stay at company Guest House.
Kallar Kahar to Naran. 2 nights stay. travel time 9 hours via Abbotabad. 1 Hour traffic jam in Abbotabad. Stayed at Ferry Meadows hotel. They charged 7.5K per night after much bargain. booked 2 rooms for 2 nights. Most Hotels were fully booked. My favorite hotel in Naran is STC Motel. It was fully booked.
Naran to Hunza (Karimabad) via Babusar ,Chilas. 8 hours drive. 2 nights stay. Hotels in Hunza were expensive and most were fully booked. Stayed at a small house converted to hotel in 4.5K per room in main bazar of Karimabad. Booked 2 rooms for 2 nights. Accommodation was just live able. Road from Naran to Hunza is mostly very good. A small patch of some 50 KM is partly average with bad patches. This is from Chilaas to Raikot Bridge. Other than that excellent roads.
Had short stay at Lulusar Lake and Babusar. It was good experience.
Hunza to Khunjrab Pass. 4 to 5 hours drive. Excellent road. Witnessed Snowfall in Khunjrab (in July). Night stay at Sost PTDC 4.5K.
Dont miss Khunjrab pass. On they way there are 6 tunnels (Attabad Tunnels) one of them is 4.5KM long. Also have a short stay at Attabad lake. Do boating if you want. Also see the Passu cones etc.
Sost to Giligit. Stayed one night with relatives there. Did some shopping of Chinese goods.
Gilgit to Naran. 7 hours drive. Stayed at a hotel on Naran Bypass. Hotel was OK not as good as Ferry Meadows but cost was Rs. 4.5K per night. Booked 2 rooms for 2 nights.
Naran to Murree via Balakot, Muzzafarabad. Road is OK with few bad patches. 6 hours to Murree.
One night stay in Murree. It was difficult to find a reasonable hotel in Budget. Booked a large room with 4 beds in 8K. Hotel and accommodation was good but only one washroom for 6 persons.
Murree to Islamabad. Stayed one night in a guest house in F7. 4K per room after bargain. Booked 2 rooms for one night. Visited few places and relatives. Dinner at Monal was a good experience. Good food and too good views.
Islamabad to DG Khan via Chakwal Mianwali Bhakker etc.
Maybe something useful for you in this.