Gearing can be a tricky one.
Take into consideration that cars usually spin-out and lose traction when too much torque is applied to the driving wheel causing them to break free.
A slow steady application of power will help to prevent your bikes rear wheel from spinning out and keep your crotch from trying to bend your bikes top-tube.
This last winter I was doing alright with 39x15 on my singlespeed mountain bike with higher pressure sorta-slicks.
Those sorta-slicks being Serfas Drifters 26x1.25.
Bring the cyclocross bike. Run it fixed and have the fun. If your toes get too and numb get off and jog the bike a little.