With the Coleman Heat Pump, you might be able to open the "fast cool" vents on the bottom of the unit for heating.
We do this and it pushes most of the heat to the floor.
We stay quite warm ( down to 40 degrees outside).
I have a Fleetwood Bounder 35 E with same problem.
Ancira in "Ft Worth" has ordered a "Lift Kit" from power gear.
If you have an Electric Slideout Fleetwood has a service bulletin SBA0267
that explains the lift kit.