Sapporo vs. Da Nang for a trip in November—which one should I choose?

‌Early November..... I'm debating whether to go to Sapporo for 3 days/2 nights or Da Nang for 4 days/2 nights.
I'll be departing from Busan......
Departing on November 7th.....
It's been a while since my last overseas trip, so I'm going alone to get some fresh air.....