Flights to Wakkanai Airport is quite expensive compared to Shin-Chitose but it will save you 6 hours of driving. I use this airport to access Rishiri and Rebun islands.

About:

Wakkanai Airport, located in Hokkaido, Japan, is the northernmost airport in the country capable of handling jet aircraft. With a 2,200-meter runway and modern terminal building, it serves as a vital transportation hub for the region. Despite its small size, Wakkanai Airport offers domestic flights to destinations like Tokyo and Sapporo. During the coldest winter months, the airport may experience closures, leading to diversions to other nearby airports.