I have just an aluminum patio cover & it has 4 posts bolted into the cement, I think it is 20 ft long. They are metal tho. I reinforced it couple of years ago as we are getting much stronger winds than we used to get. Doesn't sound like enough to me. But I'm not in construction, just helped my dad build our houses from time I was young. 1 good wind & you will have a twisted mess in my book. Much easier to add a post or 2 (at end of house where connected to house- never heard of doing that before.) don't you have any rules on adding a roof or patio cover in your town. Out here the posts have to be attached to metal brackets put into cement-usually when patio is poured. Hope you don't have a teen on a power ride-on lawn mower, just 1 backing into that 1 post & trouble!!!! Or if car or truck can get near it. Accident waiting to happen!! So your 1 post fails, what do you think will happen? How wide is it? Mine is 10 ft., I think It is also attached to house on 2 sides bolted unto the stucco every few inches. I live in earthquake country, I've seen a lot of them twisted, & they are a mess & try removing it once it is twisted & tweaked, almost impossible.

This cover is made of wood and constructed like any roof, rafters, sheathing and roofing. I appreciate the comment an accident waiting to happen with only one post. I'm going to add a second post.