Late spring in Norway brings deep green valleys, roaring waterfalls, and long daylight hours without the dense summer crowds. Aiming for May or June lets you catch the western fjords at their peak, but you'll want to lock in your plans four to five months early to secure transit and local stays.
A realistic budget from the US runs about $3,800 once you factor in flights, fjord ferries, and lodging. Spreading that cost across a year and a half makes the upfront price much easier to handle.
A 0% interest window is just a breather, not free money. If you still hold a balance on your Citi Simplicity® Credit Card after 18 months, the standard APR applies to whatever's left, so set up auto-pay for $211.11 a month from day one.