Just win faster.
I second this motion. White is the worst color for commander, so a lot of times you can beat it by ignoring it.
The downside for you is that red is the second worst. But if they are playing Elesh Norn, it means you have a 7 turn clock to beat them. I took a look at your a Krenko deck, and it seems like all you're missing is better haste enablers.
Thousand-Year Elixir will both give Krenko haste, and let's you make more goblins; both are important, because
Goblin War Strike and
Mob Justice are excellent ways of taking out one player. You can also use
Mass Hysteria,
Fervor,
Hammer of Purphoros,
Goblin Motivator, and
Generator Servant.
The other way you can go about this, is using
deception (not the card
Deception, but that might work too). Sleeve up your Krenko deck and another deck in the same colored and styled sleeves. You're allowed to keep your commander face-down until everyone has decided which deck they're going to use, but you must reveal your commander once people draw their starting hands. This way, if you're friend chooses Elesh Norn, and you didn't choose Krenko, they're
dead in the water.