you should call some local contractors to bid the job.
they will see the house, where the furnace is located
and if there is room/capicity for more vents.
heat only?

best of luck

Regarding ductwork, if the furnace is in the basement and the bedrooms on the second floor, trying to get ducts up through a closet, pantry, laundry chute or other chaseway to the second floor is your best bet. Adding insulation in the attic above the second floor would be helpful as well.

But you indicate the furnace goes off before reaching the temperature setting on the thermostat (which is presumed to be on the first floor?). The furnace going off before it reaches set temp is indicative of other problems -- it sounds like the furnace is overheating and going off on high limit. Is it a new furnace? Check that the filter is clean and not too restrictive on airflow. Be sure the vents are not blocked in the rooms. Call a contractor to evaluate the temperature rise / fan settings on the unit - and potential other issues.