While I would hesitate to say anything is impossible, a feather leaf palm in zone 6b without protection might be a little bit much. Near the coast in the PNW (zone 8a and up), I believe a few of these can grow already.

I'm not wanting to grow it here. I was trying to figure out if it could grow in Brookings Oregon which is zone 9b I think. I was wondering if they can live in a place with cool summers or if they need heat to grow.

Sorry, I misunderstood. Certainly on the coast, they should grow very well.

I believe Jubaea chilensis is either the most cold hardy feather palm, or very near the top of the list. It actually prefers the cooler west coast climates, and will not make it over here on my side of the continent.

Mixing it with Butia might make it more tolerant of our conditions on the east coast, but either plant would survive in 9b, so it stands to reason that their offspring will as well.

I always thought they had to be the same variety or something to cross pollinate? Are Jelly Palms and Chilean Wine Palms related?

Jubaea chilensis (Chilean Wine Palm)
It is a palm reaching heights of 82 ft with a trunk up to 4.3 ft in diameter at the base.
It's leaves are pinnate.
The tree grows very slowly.
It needs mild winters, but will tolerate frosts down to about 5 *F as well as relatively cool summers, making it one of the hardiest of pinnate-leaved palms.

Butia capitata (Jelly Palm)
This palms grows to about 19 feet in a slow but steady manner.
Identifiable by it's feather palm pinnate leaves that arch inwards towards a thick stout trunk.
Butia capitata is notable as one of the hardiest feather palms.
Tolerates temperatures down to about 14 *F

Sounds like those two would make a good hybrid.
If anyone is growing one I'd love to see it.

Butia x jubaea is surviving fine in Northern CA It should do fine there. They are in the same family. Along with Syagrus and Parajubaea. I just received some pollen of Parajubaea Sunkha and will be crossing it with Butia Odorata.

I have a Butia x Jubaea growing outdoors in a pot in Seattle. I've had it for three years. It started off as a quart pot starter about 12" high with just three fronds, and now it's about 30" tall and wide with a dozen slender fronds. It's dark green like Jubaea but with slender, arching fronds more like Butia in shape.