Cytuj:
In this thread the author guesses that in asoiaf a raven must be able to travel at 700miles per day, and the distance between eastwatch and dragonstone is around 2100 miles, meaning that a raven would take at least 65 hours even if they sent there most jacked raven, pumped him full of steroids and gave him a line of coke before hand. Then accounting for about an hour of reading the message, then Dany changing into snow gear, thats an extra hour.
The travel speed of a dragon is harder to guess at but from this asoiaf forum page, they surmise that they can travel at up 175mph as the most generous response. This means it would take Dany 13 hours to get to Jon and Co.
Overall then, the party must have been stuck on that rock in the middle of the (really fucking slowly) refreezing lake for nearly 90 hours, which is about 3 and a half days. Assuming they had food (crispy thoros steak) its possible to survive that, but really is a bit of a 'fuck you' to the face of logic.