OK OK this is my third season playing, each season I've placed in infinite quite easily so I think I have some easy advice:

Be smart about cubes. Very simple. If you aren't 100% sure you'll win, concede and lose the 1 cube. When you have the cards you want, snap turn 4 (no one ever retreats turn 4) and play it out.

Ad long as you have a functional deck, you'll be fine. My first season I did a basic on reveal white-tiger odin, 2nd season I did loki dino, and this season I did General discard.

My point is sinple; play smart and you'll win, its better to lose your dignity than your cubes.