If you have a car - it takes 10mins.
If you're using wdw transport - it takes longer - you would have to get a bus to Magic Kingdom. Then once at MK get a boat resort launch to Poly (quicker than monorail). I'd leave an hour to be on the safe side (waiting for buses/boat) although the bus ride takes 10mins and boat 10mins.
Hope this helps!
Ohana's great - you'll love it!