Transit in Tokyo before going to Sapporo

Hello, I'm planning to go to Hokkaido next year. So my flight from my home country will land in either Haneda or Narita Airport and then go directly to Chitose Airport.

What I want to know is how long is the usual transfer from International Arrival to Domestic Departure in both Haneda and Narita, assuming that the airline is the same (like arrive with JAL and depart with JAL)? Because some of the flight options given when I searched were around 1-2 hours transit, and I'm afraid that I can miss the flight to Chitose if something unfortunate happens.

Thank you very much!

I had this transfer last February with only about 90 minutes to work with, and we made it onto the plane. This was at Haneda. At Narita it's even easier because you don't have to go to a different terminal. Since you're buying these tickets as one purchase, one itinerary, and it's the same airline, your transfer is guaranteed. Even if you miss the connection, Tokyo to New Chitose is one of the busiest flight paths in the world, so planes are leaving constantly. They'll just put you on another flight, which shouldn't be too long of a wait. So don't worry!

There are more HND-CTS flights than NRT-CTS flights, so it's best to go to Haneda. It is more of a pain, since you'll have to change terminals.