Studying in Sapporo (HJALS) vs Tokyo?

I'm 18 years old and have taken a gap year off before going to RISD to visit Japan and Korea. I have not had any formal education to learn Japanese, but have started self studying using the Genki textbook for the past 2 months. I have made plans to go to the Hokkaido Japanese Language school in Sapporo for the school's Winter course from January to February, and afterwards study in Seoul from March to May. But I've started having second thoughts and begun to look for additional schools to study from May to July specifically on mainland Japan (such as in Tokyo or Kyoto) to return to after my time in Korea. I'm worried that studying only in Sapporo, I would not get to see very much of the rest of Japan. I really would like someone's opinion. Do you think it would be better to study in Tokyo or Sapporo from January to February and try to find a different school? Or go through with the plan I have now. I want to add that before going to Korea I have 9 days inbetween the time that my school in Sapporo ends and my studies in korea starts.