Late September in the Pacific Northwest is the sweet spot. Summer crowds go home, high mountain passes are still clear of snow, and rain stays light enough for long forest hikes. If you book your rental car in early spring, you hit that rare window where prices drop and the weather stays warm enough for a long drive.
A realistic ten-day loop runs about $2,400 for two people, covering gas, stays, and the car. Instead of dropping that all at once or putting it on a high-interest card, you can break it into small monthly chunks while you plan.
The intro window is a fixed deadline, not free money. If you still carry a balance after the 18 months, standard interest rates kick in on whatever is left, which quickly erases the savings you planned for.