I think he'd be ok if I died. I do a bunch of stuff (laundry, grocery shopping), but mostly because he hates it more than I do, not because he can't. Hmmm, he might have some trouble with the cleaning lady and gardeners, as I've dealt with them pretty exclusively.
He'd have to learn to find things again.
If he died I'd be pretty deeply fucked, as he makes the lion's share of our income and pays the big bills like property tax. I'd figure it out, I hope.