First off, having a minimum of 0. F. is the usually sited as the min. for Zone 7a. I am zone 7 but last year was soooo warm, doubt we dropped lower than 20 f. much. What general area are you located in? But to return to your question, I have usually seen Med fans listed as zone 8. It is possible to have a zone 8 microclimate in a zone 7 (near your house, southern exposure, etc.). These palms also would need excellent drainage if your climate, especially in Winter, is wet. Here, a raised bed is useful. Having said that, I did have one survive a snowy zone 6b/7a winter years ago --but it did suffer some dieback but eventually recovered. If your climate is drier, you might consider the silver/gray Med. fan as it is cold hardier but less tolerant of wettness. Keep in mine, Med fans are slow but steady growers. (one of my most massive palms is an older, containerized Med fan.). I recently planted a Med fan in a raised bed in a sunny/hot southern exposure which is probably zone 7b or 8 in the winter, but time will tell. Windmill palms and/or Sabals and Needles are other possibilities depending on your particular and microclimate possibilities. If you provide a bit more info about your location, you may get growers who can share with you their local, real world, experiences.

They seem to be similar in hardiness to Pindo Palms, in that they can take temps into the teens, but if it snows and sticks around a bit due to cold, it won't be happy. Often if this occurs it will have severe leaf damage but will grow back in the spring. It tolerates dry cold much better. If you occasionally get down to 0 F though, I don't see this working for you (wet or dry) unless you are able to give it excellent protection.

Here is a link that might be useful: Virginia Beach Weather

If you live in a dry climate, they probably can get down to 0F if its a 1 in 10 year thing (which would actually be more of a characteristic of a zone 7 climate). Mine gets protection, but I have never even worried about it because it is so tolerant of being protected. I just use christmas lights and a plastic garbage bin. The christmas lights probably add around 10F to the outside temperature, maybe more if there is snow in the ground since the snow insulates the garbage bins better, but the real benefit to winter protection is that the garbage bins keep them dry all winter.
They should be good in a true zone 8 that does not go below the teens and has milder weather in between.
Good luck!
-Alex

Agree with the posts above. I am in a borderline high 7b coastal zone. They are considered marginal here. That being said, I have three. One that was planted as a 7 gallon blue pot in a protected southern exposure, wedged in between two robust camellias seeing as wind breaks in winter. It was a mild winter with only a few light dustings of dry snow and minimal low of 14. On the few nights we had in the teens or with snow I just placed a frost blanket over it, especially since blue pots are notoriously tender the first winter or two. It is flourishing and even produced inflorescence.

The other two are also blue pots were planted as 3 gallons and out back in a more open spot. On coldest nights they got frost cloth and a large bucket over top. They both received minimal winter damage on the first two or three emerging fronds, which I cut off. They are fast growers and you'd never know they were damaged. I suppose they will get hardier, but still will have to keep snow off them. Thankfully, we historically don't get much snow and usually only in one to three inch increments.

I gave a blue Med Fan to neighbors as a gift. They planted it out front, in a less than optimal location, against my recommendation. They didn't give it any protection and it did great and is growing well. So it would be in your best interest to look for a blue or silver frond Med Fan. They are from the Atlas Mountains of North Africa and supposed to be an additional half zone hardier.

They are my favorite palm, but they do need good protected seating and winter protection when it gets super cold or deep snows. Alex may offer some additional tips, since he's been successful growing them 150 miles north of me, but also near the coast.

Good luck!

its sounds like your in new mexico, if so i would try one for a zone 8a. they should be readily available there i would think. its worth a shot!
goodluck