Welcome to TUG. First, buy where you want to use. It's just a waste of money to buy to exchange. Every exchange costs more money. And buy the size unit you need. Unless I was sure I would be using at least 2 years out of 3 in Hawaii, I wouldn't buy there. The airfare isn't getting cheaper, and those weeks/units have timesharing's highest maintenance fees, and the state of Hawaii taxes timeshares higher than anywhere.
Soooo now to your question. IF you own a 1 bedroom week in Hawaii, it's very likely to be able to trade it for a larger unit somewhere else. That takes care of the 'bigger' part. Whether it's 'better' is your call.
Others will probably chime in, but if it was me, I'd get a 2BR lock-off in a location where you can drive to if you want, then use it's trading power to either exchange into Hawaii, or split it up to use one side and exchange the other for another week somewhere else.
That's just my 2 cents worth.
Again Welcome. Stick around here for a while. You have much to learn to become an educated consumer before you buy anything.
Jim Ricks