Snow is not a problem. Sufficient insulation and snow stays solid outside the socks. You just need a larger shoe to fit those socks inside of. I wear thin moccasins, and did not find any snow last winter that I couldn't tackle with a double layer of wool boot socks.

Slush is another matter. Wool will keep you warm when wet, but can't keep the water out.

I generally take the dog to the hunting training grounds. It's pretty awful weather-wise. There are pools of icy water hidden under snow, and there are stabby spikes all over the place from the place mowing the prairie (including mowed woody-stemmed plants). I had a spike go through a minimal shoe of mine and puncture my foot... twice. My dog has had one issue over the years. It's pretty exposed weatherwise. There's no wind block or rain block.

I need more than something thin and small... it needs to be waterproof, tall, and warm.

It's gotten down to -50*. I have no desire to lose toes ;0)

PL

I owned a pair of the NEOS once. They are not breathable. The are OK for low exertion activity, but as soon as the blood gets moving a little (hiking, snowshoeing, etc.) they get way too hot for me.

Damien, in what kind of temps did you wear them? The website said they were good for up to 0 degrees, so I wonder if they would still be overly warm in -20* or so.

Casual dog mushers love those Neos overshoes, but they spend a lot of time riding, not running, and the extra insulation is helpful for them. There are several models, some of them are uninsulated.

You might find it worth investing in custom made boots. Russell Moccasin has a very good reputation, but they are a bit backlogged, so if you order now you might not have the boots this winter. You can order your tall waterproof insulated boots made on a Munson last and with a minimalist sole.

http://www.russellmoccasin.com/new_products/minimalist_footwear.html

There are many other moccasin makers you could check out if you need them sooner. Just check that they have minimalst sole options, custom fit options, and waterproofed leather options. Insulation you can take care of with extra socks, just make sure to wear said socks while doing any tracing/molding for custom fit shoes.

The ones I had were not insulated. I varied the insulation inside depending on the temperature conditions. I wore them in all kinds of weather/temperatures.

One insulated, one not. I use the non-insulated most often during rainy muddy and works great. The lined ones kept my feet warm in a Wisconsin snow storm -20 with the wind.