From my perspective. . .(the stonelord dwarf), The combat essentially felt like a regular nonmythic fight. The only really noticeable aspect would be the fact that the winter wolf acted twice in the round. Other than that though, combat went smoothly even with the lack of real cooperation due to the one-shot nature of the session and characters.
Indeed. I was the Wizard 3/Rogue 2, with a build stated as such to go into Arcane Trickster. My first actions were to cast Enlarge Person on the Barb and the Paladin, giving them exceptional reach. After that I was plenty content just to acid splash the last round. The Mythic Wolf's breath weapon hit hard, but that was about it. As said before, it seemed like the wolves were glass cannons: Able to hit hard, but could be killed in 1 hit. All in all, it felt like the dire wolves were tougher than the mythic wolf.
I felt somewhat the same way. Even considering that at least one of the players who had joined in hadn't had time to prepare his equipment and item list, the combat as Espy noted, went without a hitch. The only things that really stood out, was the fact that as stated before, the Winter wolf acted twice in the round, and had a significant bonus to it's initiative, and move speed.
I played the 5th level Str-based Bladebound Hexcrafter Magus. cast chill-touch, and I was charging, power-attacking, arcane-striking, and spellstriking my way through the whole fight, and as Sira said, aside from the breathweapon, was rather painful (Knocked 21 hp off of my total of 40). But that was really the only worrying part of the fight.
The standard Dire wolves that joined the battle during the first round didn't put up much of a fight either. That said, Had we been fighting three or more Mythic Winter Wolves, or had all the wolves been using different tactics, things might've gone differently. As it stands though, we ended the fight without much of a dent in party resources.
In the end... I suppose it felt like a regular fight, only that it had an extra gimmick to it to make things more interesting.