Is it worth investing in a large polytunnel? This is what we had to do here in the south of Scotland, at 1000' on a windy hillside. very little of 'normal' veg will grow outside well here. Beans become gnarled and blackened in the wind and cold, if they grow at all; it's just too cold for any cucurbits, so cucumbers, courgettes, squashes etc are grown in the tunnel, as are the beans; sweet corn stops growing at about a foot above the ground - sorry - 30cms; even winter brassicas and leeks can be demolished by heavy snow; I don't even try to grow tomatoes, peppers, chillies or aubergines outdoors, in fact the peppers, chillies and aubergines are grown in the greenhouse, which is inside the tunnel!
You can cut down wind by having a tunnel of windbreak fabric, but it still lets the cold rain in, and most of the wind. A polythene tunnel really pays its way in just a few years. You have to watch out for pests and be ready to deal with them promptly, and you have to keep on top of watering, or have an automatic eg gravity fed irrigation system