Eric--not a direct answer to your question, but some advice on cold weather waders from the far northeast end of the peanut gallery.
It's interesting to me that duck hunters and anglers have such different takes on waders. I was an angler long before I duck hunted, and so had a closet full of breathable waders and wading boots when I got into the sport. I used them for fishing and field work in Maine rivers from March to December, along with the occasional trip west for winter Great Lakes steelhead. Duck hunting has extended that use into January since our coastal season dates were shifted later a few years ago.
IF--and it's a big if--my waders don't leak at all, with two good layers of fleece or wool on my legs and as much insulation as I need on my upper body, I am comfortable in breathable waders even down to temps in the low teens. I have not gone lower than that, but wouldn't be afraid to try. These are stockingfoot breathables (I use Patagonia, but most of my angling friends prefer Simms), with neoprene booties over which I wear lace-up wading boots. (I absolutely detest boot foot waders . . . . .which is another rant for some day.) On the coldest days I add a set of light neoprene socks, then heavy wool socks. Most of the time I just go with heavy wool socks.
I know lots of winter anglers and almost all of them layer under breathables rather than look for insulated waders. This means buying breathables large enough to fit sufficient layers under them and still allow you to move. As a big guy, that's why I like the Patagonia Rio Gallegos, which in XXL Stout give me all the capacity I need for layers under them. The Simms seem to fit a little slimmer unless I am willing to pay for custom sizing. If you body dimensions don't run to Andre the Giant specs, they'll be fine, LOL.
Most of my non-angling duck hunting buddies seem to go the insulated route, which works for them, but I'm not changing.
By the way, based on 25 years of experience and many discussions with other anglers, I can enthusiastically recommend the higher end breathables from either Simms or Patagonia. (There is a reason you see so many fishing guides in Simms and Patagucci.) I have not yet found waders from other manufacturers that I'd really trust in cold weather. Common problems with even the better waders from other retailers are leaky seams after a bit of use, poor resistance to abrasion and wear, and leaky booties. It doesn't take much of a seep to ruin your day at 20 degrees. And it's damned easy to put a hole in most waders hunting around the barnacles, sharp rocks and multi-flora rose we have on the coast. The Patagonia and Simms waders stand up to this abuse.
You will pay for this quality, however. I often use less expensive, lighter, more comfortable breathable waders in the summer when getting wet is an inconvenience rather than a safety issue. When water and air temps are both below 40 degrees, I want the best I can get.
I find I can generally get 4 or more years out of a pair of Patagonia waders, and I use them a lot, at least 100 days per year. They are the very definition of "ridden hard and put away wet". No other wader has ever lasted me more than 2 years before the seams leaked or I poked a stick through the fabric, and most won't last a year.
