I've never heard of a canning kitchen. Do they provide the equipment? Either way, it's a great resource!
I do a bit of canning, especially the essentials like tomatoes and hot sauce (OK, it's essential for me, even if not for most folks). But I've found in this climate I can grow plenty of food to have on the table all winter. I'd much rather eat fresh broccoli and a salad with dinner than something canned, even if it's also homegrown.
As far as labor is concerned, my husband and I both work full time, so we only spend a few hours in the garden on weekends, and a few minutes harvesting on weeknights, and still manage to grow much of what we eat. Obviously, with more land and more mouths, the time commitment will go up, but it doesn't need to be huge.
I also haven't had a lot of luck with 3 sisters. Remember that it was originally used for corn and beans that are harvested dry at the end of the season and winter squash. Substituting the things we like (sweet corn, snap beans, and summer squash) left me with a tangled mess of bean vines that made a teepee supported by the leaning and smothered corn stalks, and zucchini big enough to use as weapons that I couldn't reach to harvest. Or, in other years, with giant zucchini plants that grew too fast and shaded out the other seedlings, so I got dead beans, stunted corn, and more squash than I could use. Not knocking on companion planting overall - I plan to do lots of herbs and flowers (more for pest-deterrance than looks) in my veggie beds next year, and have several mixed beds already for winter crops - but this combination has been rather frustrating for me.
