Does the virus viability window increase in a colder and dryer environment? Will a Ebola viron remain viable in suspended droplet form or on environmental surfaces for longer periods of time in a cold environment?
Because if true, then even if it doesn`t significantly increase airborne exposure risk, if it increases surface survivability, it`s still a game changer as far as contact exposure.
In a lab, organisms are kept in controlled environments. Natural environments tend to be quite variable. Biological molecules do not tolerate variability very well--the more frequently the temperature changes, especially between freezing and non-freezing temperatures, the more damaged those molecules become.
In short, I don't expect the virus would survive long outside of a controlled environment.
Droplets fall to the ground pretty quickly, so you aren't likely to be exposed unless you walk barefoot... which you shouldn't be doing if you know someone is sick nearby.
The chance that you will ever see someone with Ebola is extremely small (unless you are volunteering to go help out in Africa)--but if you *do* ever come across a situation where a symptomatic Ebola patient has been in the area, you want to sterilize every surface that patient has touched. Bleach is very effective at killing virus.
...and a ridiculous number of people will remove a glove with their teeth.