Your mention of Summer Kitchens brought back childhood memories. My family lived with my Maternal Grandfather when I was about 10. Grandfather's old house was still standing and I used to go up there and play in and around the house all the time.
It had a kitchen with a cook stove, and countertop, and a big window, but no sink. There was a well right outside the back door and it had good, cold, clean water. My mom used it for canning. I remember washing lots of Mason quart jars in a #3 wash tub outside, while mom was in that hot kitchen cooking and canning all kinds of vegetables. Then when the blackberries ripened, she made her jelly and jam.
Most of the historical mansions that I have toured all used a summer kitchen. How lucky they were. What I have to do is turn on the fan. I don't use the oven too much in the hot months, but I do use the broiler.
Annie, it sounds like you have a good plan for preserving and putting up food for winter. I hope it won't be too hot for you.
Peace & Plenty