He seemed pretty confident no gi.
How well could he handle himself in gi?
Well he's a black belt... I remember him saying he had annual gi day at his gym. They wore the gi one day out of the whole year. This was years ago, and things may have changed, but I think he hardly ever trains in the gi. But I'm sure at the level he's at, and with how long he's been training, he would be very competent in the gi. 
i don't think he cares, he barely uses it but seeing how good he is nogi, he'd be competent at least
maybe not a world beater but pretty sure he is extremely competent with it.
Bet he taps many of those Gracie Barra guys who got their black belts under instructors they've only trained with during a mandatory 2 hour affiliation seminar... 