Indie is really feeling the heat and humidity and wilting when we go out. Even early in the morning when the temps aren't much higher than 80, the humidity is so bad, he's wanting to head home after 15 minutes. He really needs to keep up the exercise to keep his joints strong and lose a few pounds to get to his optimum weight. His undercoat has just been a nightmare this year. I've stripped it out 4 times so far and about a week later, he's thick and furry again. I don't get it but it's getting old and I think it's adding to his discomfort. I love his coat from the waist forward, it's long and silky and nice. Easy to get a brush/slicker/rake through too. But from the waist back is a nightmare. It's kinky, wiry, thick, dense, long and a pain to get anything through. So, he's got an appointment next week with a real groomer for a deshed treatment. I'm hoping they can do a better job than I can to get that heavy undercoat gone once and for all. I'm also considering having him trimmed to see if that helps.
Here's what he looks like now, with a little less butt because I've tried to trim it a little with thinning shears but didn't want to butcher him.

I'm torn between asking for the Golden trim that TAOofGoldyShep got in this thread:
Golden Doo
or going whole hog and having him trimmed even shorter like this to make him more comfortable.

I've stopped taking him out in direct sunlight already because of how he seems to get more uncomfortable in the sunshine (we walk in the shade near the lake or at a local park that has woods) so I don't think sunburn would be an issue with this type of cut. My biggest worry is that when it grows out, the whole coat could end up wiry and unruly like his back end already is. I've tried heavy conditioning on the rear and it just doesn't seem to make a difference in the texture. It traps everything, leaves, twigs, dirt, etc. It's just a tremendous pain. I don't mind brushing it out every night, but with this added evidence that he's not tolerating the heat very well, I want to make him as comfy as possible.
So, groomers and owners alike, what do you think? Have you had problems or changes in coat texture after cutting the coat? Have you used a "cool coat" on a long coated breed like this with any success? Should I try a backpack with gel ice packs in it? Which cut do you think would be a better choice?