I have some points these might help you
Don't spend much time gilgit city.
Spend 1 to 2 days in naltar to feel real nature.
Spend a night beside to attabad lake.
From attabad to khunjerab enjoy the road side views, although few lakes on both sides but that might take you some extra days to explore those.
Visit deosai, if it is not covered woth snow in these days.
And fairy meadows if you have more days