It will take a few years for it to reach the 5′ height. If you are starting from seed then just let it grow for a season and it will probably put on a foot or so each year. By the time it reaches the 5 foot height it will probably need about a 12 inch pot. I also live in New England near the ocean and have 3 palm trees I keep out doors year round. They are windmill palms and survive the winter months. It is a Trachycarpus fortunei and will take temps to -15 degrees F. The cold and snow don’t bother it and is a sight to see with all the snow covering it. I bought them from Ty Ty nurseries for about $58.00 dollars a piece at 4-5 foot tall. Try looking up cold hardy palms and google Oak Bay palms, Canada to see them growing in Canada. This is known as the Palm tree capital of Canada. If you love palm trees then you should try these.