Do you think you can sleep on the 2-3-2 J? If that's a 73Z, I've had bad experiences in the past when the whole cabin was filled with op-ups and it was noisy like in a wet market.

Of course you can catch some shut eye later at ...I would have recommended the 'bench'-like sofas at the Cabin, but I think the new Pier J has some day beds designated for sleeping.

Or else, the 6:45am seems to be on time mostly. I have been on 806 some times when they held back departure to wait for incoming connections, maybe the rebooking cost is high for a once-daily service. But if you really do miss, they will reroute you through LAX, which is a fine airport to transit in...

YMMV