Internal Flight/connection Islamabad - Gilgit

[diegoclemente]

Hi!
I land (I travel with my brother) in ISL on april 5th at 3:45am and I'm planning to jump on a PIA flight to Gilgit that leaves at 8am on the same day (still need to book it).
I think that if my original flight is not too late that should be plenty of time, however I was wondering if there's anything I should know (beside the well-known weather related cancellation risk) before I book it (or try, I read a lot of feedbacks about problems with the PIA online website).

I read about the need to reconfirm the flight, but we will be travelling the whole day before (and we will start our trip from different cities, even if we'll board the same flight from Istanbul to Islamabad) so I was wondering about that. Anything else beside that?

*I also have a back up plan, as there's a flight to Skardu on april 5th at 10:30 am if our original flight is late or cancelled we are keen to change plan and go to Skardu first. We basically wanna avoid a day in Islamabad as our trip is only 12 days.
Does anyone know if in case we can change our reservation (probably at cost, unless the flight to Gilgit is cancelled, but that's fine) on the spot at ISL airport?

Or is generally possible/better to land in ISL and buy a ticket there on the same day? I read this is mostly impossible in summer as those flights fill fast, but maybe early april ain't that busy?

Thanks for the help!