This
reddit user did the math (approximations and assumptions galore), but it comes out to about a 2000 mile trip from Eastwatch to & from Dragonstone. They assume the raven has flight characteristics of a carrier pigeon (about 1100 miles at 50/mph without rest) and 8 hours of rest for the Raven. Unfortunately I think they also assume the same speed/distance for a Dragon, which I would assume would be much faster. But it's not real so who knows.
Since I
think they only showed night one time, it'd be odd to match the conclusion of approximately 4 days for the Raven to reach Dragonstone and Dany to make it to them without loss of life. But the fact that the time for the Raven/Dragon/Dany to travel matches the approximate time it would take for the ice to freeze is pretty cool.