[X] Sansa will marry Lord Harrold Arryn and become Lady of the Vale, renewing ties to the North and Riverlands.
[X] No.
It's a powerful move Stannis (or rather Davos, truly that man is wasted on Stannis) has carried out here. Purely on instinct, I actually want to say yes. I did not expect that.
And yet, thinking rationally about it, it's still a poor choice.
What do we want? Do we want the Iron Throne?
Fuck no.
The Iron Throne is schmuck bait. We win it, we'll have to hold it. We hold it, we'll have to deal with any gods-damned contender who wants it. Quite possibly including a false dragon employing the Golden Company, and a lady in possession of three real dragons. And once you're on that throne, there's no way back. You either keep it, or you die.
What do we actually want? We want peace. We want safety for the North and our family.
Renly's numerical superiority over Stannis is such, that even with our forces on Stannis's side, the issue would still be very much in doubt. And while Stannis is superior in skill, Renly has Tarly working for him. And has the reserves to absorb several painful defeats to teach him the humility to listen and still win afterwards.
Pretty much the only scenario where Stannis wins is one where Renly dies due to some freak occurrence. Without Melisandre in play, we can't count on that. And even in canon, Renly was not foolish enough to lead from the front.
Meanwhile, if Renly wins and we haven't gotten involved with Stannis, all we need to do to achieve our goals is to bend the knee.
Don't be blinded by sentimentality or ambition. Do what it is right for the North, our family and our subjects and vote no.