From what I understand, the bigger problem with straight ethanol (or high % of it) is that it doesn't vaporize worth a damn at low temperatures - it has a very low vapor pressure. I believe the relavent temperature is around 5 degrees Celsius or so.
See post #3.
Also, in the work cited, Mr. Matheson addresses this point too:
In addition to the carburetor jets, there is also the problem of cold starting. As mentioned earlier, alcohol has a higher latent heat of vaporization than gasoline and requires more manifold heat to keep the mixture in the vapor state. With most engines there will be no problem that can't be solved by installing a higher temperature thermostat since the engine runs fine as soon as it is warmed up. However, the engine will be difficult to start, especially in cold weather. The easiest solution to this problem is simply to start the engine on gasoline and, after it has warmed up, switch to alcohol. To accomplish this, merely install a small gasoline tank located, perhaps, under the hood and a selector valve mounted in some convenient location near the driver.