When the water is between 32 and 38 degress, we do very well on spawn sacks, waxworms, and stoneflies drifted under floats in frog water. Our fish bail out of the faster water, as soon as the mercury drops down to about 36 or less. Spawn tends to do great for us, the colder the water is. The temps you are referring to are the same as our water temps from late November through Mid to late March. Have you every caught a steelhead in -20 weather fishing through a hole in the ice with tiny tear drop jigs tipped with wax worms? Try it, you'll like it.