But bro, the show has DRAGONS and ZOMBIES!!! Why do you have to be consistent with established rules in said universe when theres magic!!!
You should just be able to have characters move around and meet and or turn up and save whoever they like. Who cares if theres no time to get on a horse and die 2seconds later the show has MAGIC!! Littlefinger can fly didnt you know and Gendry is faster than usain bolt and doesnt need energy to run he can just run forever because magic is in the show and hes a baratheon. Yeah the show didnt need to show that, you should just know