I kept a traveler's palm on a 30 gallon tub for years, it got too big for me to lug it in and out of the greenhouse. I have a 20 ft ceiling, so could have accommodated it, but had no place to plant it in the ground. I eventually planted it out, it freezes about every other year and comes back, so needless to say its never gained any size.
CalPoly 5 years is doing good LOL.
Some folks here have managed to keep them up by the house and they have gotten 8 or so feet tall in between freezes, but I don't know a single person here who has ever had a bloom. We don't get the orange birds to bloom here either...its too wet in summer