WS
Brother do go on the trip by yourself. Tour operators try to save money and for that they try to spend as much time in road as they can especially at night so they do not have to keep you in a hotel.
Best is to find a friend or two to accompany you. This will keep you company and cut the cost per person.
For solo I suggest you go to abbottabad - Naran- chilas - Gilgit - Hunza - Khunjerab Pass - Skardu. To cut the cost do not stay in Naran stay in a place a little after Naran called Batakundi. And do not stay in Karimabad Hunza instead stay in Aliabad. This will save you some money.
Since you have your own car you can stop at any spot you like and enjoy the scenery.
Tip for travel: try to start your day at 5:30am - 6:00am you should be on the road and should be in your hotel by Maghrib time. DO NOT travel at night in hilly areas