Sounds like the 6D would be better for your needs.
I think you'll find topping out at ISO 3200 to be a real drag, when you could get 3 more stops of ISO performance from the 6D for those low light events. That's the difference between motion blur, and no motion blur. For portraits it's near meaningless unless you're doing natural light only and doing lots of night shots. For events when you're not using flash, the more ISO the better, if it's clean. And the 6D's is as clean as it gets. I would only get a 1D series for "general" use if you could get a more modern 1D and had the money to burn (like a 1DIV or better). But for basically general use like you're looking at, I'd be looking at the most modern sensor for the money, and the 6D pretty much has it, short of the three times and higher more expensive modern 1D series.
In my book:
6D for portraits and general stuff requiring lots of lovely ISO.
1DIV for wildlife, adventure shooting, etc, where you encounter more environmental hazards.