twenty_over wrote:
Can anyone offer suggestions as to how I can get the upstairs cooler...

Put the furnace fan to 'on' rather than 'auto'.

Consider room airconditioners for upstairs.
They are inexpensive. New ones are efficient.
On some days, you may need to only run the window units
to cool upstairs.
If you come home to a hot house after being away for a while,
running the window units and the central a/c will cool the house
faster.
If you sleep upstairs, and you like it cool at night, you could keep
the bedroom colder and not have to cool the entire house that much.
When we added two window units upstairs, we used the central a/c a lot
less
and our total electric bill was significantly lower.

Lena