What about transmission fluid? Double check your tyres condition and suspension system.
Also check Spark plugs as well as Brake fluid flushing etc. too
Keep extra tyre, oil, coolant in your car.
With frequent stop and moderate speed as well as light shopping, you can easily reach within 24 hours but if you are fond of eating Local Foods like Butt dee Karahi or Moro kaa special Kunna then take this trip to 27 hours
One can understand 100% work there from Karachi's situation after recent rain.
Yes, not so much work required if you live "Pul k Us paar; means DHA/Clifton/Bath Island areas)
In my personal opinion, frequent rest to yourself as well as your car is mandatory, people easily take PKDM Alto so no worries if your car is in good condiion.