I installed an engine block heater with the hopes it would help with cold starts using e85. Even in my garage where it hovers around 50*F, it takes 10-15 turns of the key to get it to start. Well, after leaving it plugged in over night last night, it started up on the first try. On top of that, coolant temps upon start up were at 108*F, totally by passing the cold start cycle which wastes tons of fuel. Couldn't be happier.
So, if you're running e85 and having troubles with cold starts, I highly recommend an engine block heater. I put mine on a timer too so that it kicks on 2-3 hours before I leave for work, just so I'm not wasting electricity.