Now that's some detecting passion!

I wish I was sitting there with ya!
About the Summer hunts.... you can definitely have some success, just might take a little more scouting for a site. My best copper count for a day (28) was in June or July. The site also turned up a rare local coin that basically bought a detector, and a good button that was worth about two. Nothing like being out on a sunny day in a hay field popping old finds!
As for the copper to button ratio, I tend to think a lot of your sites are sparse for finds and you're finding the coppers by covering a lot of ground. The difference here is every place we hunt is an old house site that is loaded with iron, and all the usual targets to go with it. If we go to a field, even if we hit an old copper, if there is no site to hunt we move on. There's much better waiting for us here then to hunt dead ground for several hours and only dig 10 targets, even if a few of them are coins. Also, it's not uncommon to find two old sites side by side, or one old one on the water, and one maybe 20-30 years later mid field, and even a late 1800s one at the road. I don't post the old trash but we tend to dig way more than what's shown in the posts. Detecting is a numbers game, the more old targets you dig, the better chance of decent keepers!