No, you're not nuts, but I wouldn't purchase anything larger than 15 gallons in case it doesn't work out. I've heard of people planting windmill palm...

I'd like to see some of these New Zealand palms! Try to post some pictures. I never really knew what the climate was down there.

on well, it's half the fun trying to grow plants/trees like this in areas that are not supposed to grow! I'll just cross my fingers

We'll all have to keep one another informed when cold weather hits - perhaps we could help keep each other's plants alive with our mutual ideas! Luck...