Our heroes traveled for what seemed like most of the day before being surrounded, but let's say it was 15 miles. They send Robert-lite to run to Castle Black.
Let's be generous and say he makes it there after about 3 hours of running.
They find him outside the gate when he's half dead and can't even talk. Going to be a minimum of 30 minutes until they can get the exact location of Jon & co + what they need + the message written and a raven sent.
The Wall is about 1000 miles from Dragonstone. Ravens can fly ~300 miles..... in a day.
But the raven arrives at Dragonstone. It gets received, Dany does some arguing about it, chooses a fancy wardrobe, etc. 30-60 minutes again.
Then she flies from Dragonstone to beyond the Wall. On a dragon, that are in the same ballpark as ravens speedwise, from everything we know and have seen. And ravens travel 300 miles in a day.
So all of this, the 2000 mile journey, the 15+ mile run, the writing of messages and receiving and arguing and getting dressed, etc...
Happens while Jon and company are surrounded, the light doesn't change, and nothing suggests they were stuck there longer than some hours at the most.
10/10 writing imo