New Chitose Airport: In ski season, take a reserved direct resort coach to Hirafu Welcome Center or your accommodation stop. It is the sensible choice with ski bags: allow 3–4 hours in snow and roughly ¥5,000–6,000 one way; schedules and stops change each winter. The rail alternative is Airport train to Otaru, then a local train to Kutchan and a bus/taxi to Hirafu—usually slower, with multiple luggage transfers.
Kutchan Station: Kutchan is Hirafu’s useful railhead, not Niseko Station. In winter, use the local bus or pre-booked taxi for the roughly 20-minute run to Hirafu; do not assume a taxi will be waiting late at night. From Sapporo, rail via Otaru generally takes about 3 hours to Kutchan.
Sapporo Station: Use the seasonal direct coach if its timing works, or train via Otaru to Kutchan. The evening Niseko Liner can run directly to Kutchan in season, but it is not an all-day service; check the current timetable rather than planning around it.