Not terribly realistic. You should allow for three hours between landing, checking in at a resort and getting to your first park/restaurant. And that's if everything goes according to plan. You have no idea how long it will take to deplane, or if your flight will be delayed.
A couple of other things working against you: Your ADR is 25 minutes before 'Ohana stops seating people, so it leaves you with virtually no cushion to be late. Also, 'Ohana is a credit card guaranteed restaurant, meaning they will charge you $10 per person if you miss the ADR.
I'd try for 'Ohana on a different night and maybe either eat at your resort or at a park the first night.