PVC winter tarp frame:
No screws, no metal hardware or sharp edges to rip covering, nothing but rope and PVC (boat friendly), easy to set up and easy to store and open inside space for working. Can be made taller or shorter for your needs.
With the pitched short roof snow was not an issue so no structural ridge beam is needed, as long as there is no roof load. You can also use a 90 deg. elbow at the to ridge to get more pitch, but you will then have to tie center rope off to mast to keep for side to side movement or add interior rope gussets. And if in doubt, add a rope from the 45 deg elbow to the other 45 deg elbow on each frame section.