Why is cold mud so sticky?

As keen as I am on mud, I just can’t get on with moist clay soils between about 1 and 5 degrees Celcius, and in particular, recently defrosted mud. It’s so sticky that tyres and boots just get clagged up. I’m sure hikers have noticed it, and I sure noticed it out mountain biking last week, as it just about tripled the weight of my bike. A thawing frost is the only time it gets this mudbound, and the same mud at a slightly higher temperature won’t be as sticky.

I’m pretty sure it’s not extra cohesion due to ice crystals in the mud, as it’s generally too warm for that, but as the relative viscosity of water doesn’t change significantly with temperature I’m stumped for an answer. What’s going on? It’s more of a clay than a loam thing, so maybe potters and ceramicists may have some insights.