Are more portals better, inside?

I'm make the underworld labryinths for my game in quark. Their basically made from many small adjoining square rooms, each one with 1 to 4 doors leading to the next rooms.

I know I need a portal on the "front-door". Should I also put portals on the door between each room - effectivly makeing each room it's own zone?

Or would it be preferable to have the entire interior as one zone?

I found out if the portals/zones are broken, it rains indoors. That aside I haven't fully wrapped my head around the concept yet so I need a little guidance here.

Thanks!