Believe they are both 80 minutes long.
Just wanted to make sure, I don't venture into this subforum often. We do see Euron acting all surprised and he is looking up at the sky so whatever surprise is coming, it's coming from above. Still possible we'll see Yara and her fleet, I don't even remember if we seen her this season? Don't remember what episode Theon said goodbye to her in, to head off to Winterfell.
We do see Big D all alone and Tyrion approaching her cautiously (even more cautiously later on) so cat is probably out the bag with Jon snow revelation next episode. Whatever happens with that will probably wait until last episode though as the battle will be the centre point of Episode 5.
There is a dark shadowy figure in the shot of the Golden Company marching, looks a little too tall for Arya but someone has definitely infiltrated the King's Landing. Most likely it's Jaime? Between Arya travelling with the Hound and Jaime possibly after his sister, that story arc will be the showdown between Cersei and whoever get in line first to kill her, as well as Mountain protecting her with his little brother after his head. Which is probably the only way to kill him in his zombie state