Great question! I dug around and here are some thoughts.
Regarding hoop house and whether or not its a good idea or even necessary. Here is a link to a publication from WA, titled "How cold can you go?", that provides some good information:
http://hortsci.ashspublications.org/content/43/7/1966.full
In that that publication, Figure 4 shows bud critical temperatures for Reisling. Bottom line is that bud hardiness is a function of time of year. For Reisling during dormancy, bud hardiness is between 0 F in early November to -11 F throughout the winter.
For Perry Ohio, average monthly minimum temperatures are nowhere near the critical temperatures for Reisling. Record lows during the months of December and January are -19F and -11F respectively. So there is some risk of cold damage at the extreme. Is it worth building a hoop house to protect from the worst case condition? I wouldn't think so but that's your decision to make.
In the same publication, they cite growers that bury waterspouts growing near ground level (but above the grafted rootstock) during winter in case of extreme weather. That way, they may lose the main growth but the vine will be able recover.
On your site, a slope will help drain your area of cold air so some thought to prevention of cold air pools might be more effective than a hoop house to prevent damage from cold.
Regarding wind, there are some references that indicate high wind throughout the growing season can result in less vigorous growth. Also the canopy in the summer can cause high load on the trellis due to wind drag. Perhaps think about orienting the trellis to give wind a path down the row rather than across it. Also, some trellis designs are more robust than others. A link to different trellis designs can be found here:
http://ucanr.org/sites/intvit/files/24348.pdf
Anyway, thanks for the great question. I hope everything works out for you.