Summer grape vine pruning

That’s very helpful DC.
Btw, here’s last years harvest:

The covered area is about 12’x7’. The single trunk/cordon used last year was about 4’. I left some spurs, and I left most of the new shoots, and thinned to 1 bunch per shoot,. I harvested 36 large good sweet bunches in total between the 2 vines. That means I had about 36 shoots in total. I haven’t pruned or weighed yet. Looking at the vine now, all of the last year’s growth has much more than 8 buds, Dozens in some cases with the growth having expanded up to 15 feet. The covered areas were pretty full of foliage with a lot of foliage extending out into the rain.

If I have the lingo right, Im thinking of a single cordon spur or cane pruning system. Basically what I did last year, but keep as many spurs or canes as I can on the Cordon. lots of room for expansion, but I may not have enough new shoots. Unless I can place say 2 bunches per shoot?
If I create new cordon’s this year, there’s not that much room, unless the new shoots stay much smaller than they did last year. Placement of the new thickest vigorous cordons May be difficult to get symmetrical. If I increase shoots numbers , will their size shrink?