Have you asked Infratech?

No wind block. No sitting around.

I did. I actually called them this afternoon after I posted this.
He just told me to go to there website under frequency asked questions.
And based on my size I would need 6 heaters.
This is their answer to how much heat to expect:

At their Food Services Testing Center, Pacific Gas & Electric has determined that a good patio heat installation (gas or electric) will provide between 3-7° of perceived heat at 60° F ambient conditions. Test results determined that more than 7° is too warm to sit in for extended periods. Colder or draftier areas may require more heat; protected or warmer areas may require less. Every installation will vary, along with our customers’ expectations.

I take this as if it’s 40 F the heaters would only increase the temp to a max of 47 F ?
And like dan188& said above with nothing blocking the wind I probably won’t get much increase at all.

I would love to sit out here and watch football and be semi comfortable. But this just seems like such an expense that I am not sure would help all that much.

Anyone with real life experiences with this?

Not specifically with that brand but infrared patio heaters are very common on the west coast to extend outdoor dining opportunities into the cooler times of the year.

I recall an outdoor pierside dining experience in San Clemente, CA in early January that was perfectly comfortable due to infrared heaters. They are also used all winter to heat an open-air ferry passenger waiting area in my neighborhood. Conditions close to oceans or large bodies of water can be both windy and chilly in winter but the heaters make it bearable.

I think in combo with a fireplace, your outdoor pavilion would be pretty comfy in all but the coldest weather with a couple of carefully placed heaters.

I have the same infared heaters on an outdoor covered porch that is 20x16. They work great, I love them. I have four of them in the ceiling which is 12' high. My porch is only open on 2 sides. The wind is the big weakness. If it is windy it takes away about half of the heat. Mine take the bite out the chill. They actually work better on a cold summer night when you have skin exposed because that's really where you feel the infared heat. When you are bundled up watching football in the fall you will lose a lot of that. Your face is the only thing that will really feel the heat. I will post pics in a little bit. Overall I am happy I have them, but just realize they won't help much in cold temps with wind.

The total install gets expensive, and if you end up not really using them it would be pretty disappointing. What about portable LP freestanding heaters, if you have the height? Try one for a few hundred bucks, if it works good then get a couple more

Or light up your fireplace before you have a party out there ;)