Recommended hub motor for fat bike with trailer/heavy loads
So, I'm building a Surley Pugsley (with a non-offset Moonlander fork) to be my winter bike, and I happened across a blog post showing a fat bike with a front hub motor. I'm intrigued, especially since I'm also planning on building a heavy-duty trailer to haul appliances and stacks of bikes/scrap wood/compost. An assist would be helpful when I'm hauling 500 lbs of steel across a frozen lake. (yes, I will be buying those studded 45North fatbike tires).
Specifications I'm looking for:
1. I'm not concerned with speed so much as torque, pulling ability, and length of battery life under extreme conditions both in terms of weather (last winter the temperature here stayed below -5 for two weeks straight) and heavy loads. I do have an external outlet at my house so the battery charge length requirement is variable.
2. I don't need or want a powered front wheel all the time, for example in summer when using the Pugs to go mudding for fun. So I'll be building two front wheels, one powered and one not. Therefore, I would prefer something with a battery and control system that is reasonably simple to switch in and out, not something with 20 different clamps, although I suppose if it's essential this requirement is subordinate to #1 .
3. This may be a moot point since I know almost nothing about e-bike control systems, but I would prefer something other than a twist-grip, motorcycle-style throttle since those can get dicey when riding with thick gloves.