Nagano best advanded skiing? (+fuji, hokkaid recs..)

i'm planning to travel a bit after i'm finally done with classes end of jan and wanted to go to nagano to ski for 3/4 days! i'm an advanced skiier (skiing since i was 4) and love to explore the mountains. i've seen the main 2 areas being Hakuba and Shiga Kogen, but not entirely sure which to pick. has anyone ever been and can give some recs? 🙂 I'd also have to rent ski gear including helmet…
after that i plan to take the train/bus to Kawaguchiko since i've never properly seen mt fuji yet and then tokyo to go to hokkaido. mainly wanna check out sapporo there and maybe maybe ski one day in niseko if my wallet allows it. other than sapporo, are there any off-the-beaten path spots in hokkaido (esp in sapporo vicinity) that you'd recommend? i plan to stay for around 5 days. Any insight/tips/personal experience is appreciated! 🙂

by stenesis