It is not too early at all to be throwing cranks on Banks for smallies.  I recall a tournament that Chris S. and I fished early one year and the water temp was near 45.  I caught three fish on a crank and two were largemouth!!  I am sure he remembers.  The key was maintaining contact with structure.  That may have been the bottom, large rocks and boulders, emerging grasses, etc.

Early crank bait fishing at Banks is a good thing.  Buttt I was there this week-end 22 and 23 and Well the Bass didn't agree as much as the slimmers did thats for sure. We caught over twenty in the 3 to 6lb range "trout" that is.I have that slimy junk all over my boat, it's going to take a week to clean off.    High winds but not too cold. Did  trick a couple of Bass to bite. Over two pounds each. 

Why too much slim all over all the Bass Gear for this ole boy. 

The water on Saturday was 42 and on Sunday it dropped back to 40 so go figure?  Good luck and tight lines.