So this year's New York Fall allowed me to make my boat cover just in time before it gets horribly cold to do this!
This year, I've used tall PVC Pipe for the frame-work.
I started with cross-hitches of twine on the horizontal mast and verticals. I only used nylon twine for all this work, and to tie the bases of the supports to strong points on the boat so that any shear forces can be checked. I used masking tape sparingly - works very well but I plan not to see myself working with Goof Off too much in the Spring.
The height of the verticals is needed to create a steep slope to let the snow melt and slide down. If the slope is not steep, the snow will accumulate and form ice-dams that will bring everything down. (One year I had simply thrown a tarp on the horizontal mast and over the side railings/life-lines. My heart would bleed every time I looked out of my bedroom window and see huge frozen pools of water on both sides of the mast, bending my mast into a curve of at least 4 inches
at the center-point. Lifting up those ice blocks was extremely hard in the cold winters! 
)Also note that, the higher you go, the stronger your framework has to be since now your tent is providing all that windage to the wind to tip it all over!
The framing is needed since the braces/rafters (??) will ease off the weight of the tarp (due to wind, plus snow, plus ice, in a few weeks) at the tops of the pvc poles. There's ample bubble-wrap, and rags, and masking tape, there to make the sharp edges bluff so that they don't cut into the tarp. The bordering edges of the tarp were tied down to the trailer with individual ties. The idea was to not bear down on the tarp and framing too much - this would cause tears in the tarp and might even bring down my flimsy frame
And also not to leave slack to have the wind get caught and cause the tarp to flap around; that would only tear the tarp and leave marks on the boat.Normally, I'd remove the jib and hang it under my deck in the back of the house, but this time I chose to leave everything on the boat. If it can survive under the deck, it can survive very well under the tarp! I left EVERYTHING as is, on the boat, as you can see. Spring time will be easy - I don't think there will be too much deterioration due to weather!
I'm contemplating covering the back too (I have additional tarp). And then could put a space heater in the boat (on deck) to warm up the tarp (to allow any sticking snow and ice to slide down. I can always control the switching on and off of the heater from its plug point in the wall outside the house. In the earlier winters I had a Thermal Switch (switches on at 45 deg and off at... I forget, 65 maybe....) inside the boat, with a heater - was quite kewl
to have this, but, uber-kewl is not always needed!My main issue is(a) protecting the boat from sunlight for 5-6 months and (b) from snow weighing down on some points on the boat, and (c) unnecessary water ingress into the boat, and lastly, (d) providing some protection against the weather.
Overall cost approximations for the project:- $50 for pipes, $20 for twine, $90 for 9.5 mil tarp of 20' x 30', $5 for masking tape.
Time: This can be done in a single weekend with another hand to help. I work single-handed, "employment at will", delivering all other weekend projects along with this stuff to the Admiral. Of course, boat-work in the fall and spring (and summer!) is priority, but there is life outside of my sailboat too.
Photos here:- https://photos.app.goo.gl/RJGt3NFB8ToR9gGg8
(In case the link is parsed off from this post .... h t t p : / / pho tos.a pp.g oo. gl/RJGt3NFB8ToR9gGg8)
on it and whole lot more personal time setting up, taking down and periodically clearing ice & snow off after each storm than the shed would have cost.