Temperature makes a huge difference to all stages of plant growth and production. But there is something that is not being discussed that affects plant growth and that is the light frequencies. If the sun isn't emitting the same light frequencies in the same quantities, this will also greatly affect plant growth, regardless of temperature. If you are in a situation where you can grow your own, I suggest you invest in a large steel greenhouse, and wind power energy to light it. Solar wont be anywhere near as efficient if the sun is brain dead, and only works in the day. Providing extra lighting will solve both problems in a greenhouse by supplementing light and generating some heat. A greenhouse needs to be strong if there is going to be more snow and gale force conditions, so use a steel frame, not a lightweight one, and if you can get hold of some reclaimed double glazing windows that are toughened glass to glaze it, rather than polycarb, poly-tunnel plastic or flimsy greenhouse glass. You want something that can withstand 100 mph winds and heavy snow
Cool
Sorry Folk's no ice age coming !