Hardiness likely to vary a bit with particular variety, small specimens of those turning out to be possibly subject to injury in your area could be wrapped or have shelters built around them - if it seemed worth bothering this much. If one or two kinds die back some winter, might make more sense just to replace with hardier selections.

Here is a link that might be useful: University of Wisconsin Urban Horticulture Fruits & Vegetables

t-ra:

When you say your are "starting simple", does that mean that you planted the grapevine, peach and apple trees yourself, or did you inherit someone else's planting? If you planted them yourself, do you know what the varieties are? It could make a difference for the grapes and peach. Apples should be ok with no protection against cold, but what does "well established" mean in terms of years in the ground?

Most grape varieties should be fine in a 5a climate, and some peach varieties will be too. But it will make a difference, particularly for the peach, if you are near a large body of water to moderate spring temperatures. You should supply your location if you want advice on that aspect of peach growing.

For many people in the upper midwest, the biggest winter problem is chewing of young trees by rodents and rabbits. Wrapping with wire seems to be the best way to prevent this. If you have a deer problem, the only real solutions are to surround a tree with a strong wire fence, or shoot the deer. Shooting is a more permanent solution, and also supplies venison.

Don Yellman, Great Falls, VA