Alaska in the summer gives you endless daylight, massive glaciers, and wildlife you will not see anywhere else. Going between June and August gets you the warmest weather and open park roads, but it also means peak season prices for flights and lodging.
A typical trip runs about $520 for your core expenses, which can bite all at once if you are not ready. Spreading that out over time makes the upfront hit a lot easier to swallow.
Remember that the 0% intro APR for 15 months on purchases and balance transfers is a deadline, not free money. If you still have a balance left when those 15 months are up, interest will kick in on what you owe.