I've considered the seasonal nature of Ebola-chan before and you're not totally incorrect.
Decreasing temperature and exposure to sun's UV rays does increase survival of EBV from mere days to several weeks or even months on optimal, porous surfaces (clothing, corpses, etc.)
Also, when it comes to influenza, cold weather (or climate for that matter) means also dry air. Dry air keep viruses airborne for longer periods of time, increasing infectivity via merely breathing the same air as another person so it's not only surface contamination that is increased.
___
On the opposite side: every season in Africa is hot. Seasons merely mean "dry" vs "wet", summer being the wet one. Ironically, Ebola-chan has been confirmed as a summer girl which might seem contradictory to the idea of increased transmission for dry air. (But it's not necessarily counter-reality if primary means of contraction is not via air, or if "dry" season is still moist enough to prevent airborne transmission. Why EBV peaks during late summer and autumn is probably still a mystery. Maybe the cloud cover of the rainy season reduces sterilizing UV-radiation or maybe it has something to do with wildlife acting as carriers to EBV.)
I'm pretty confident that an Ebola outbreak in northern hemisphere during the peak cold winter would wreak absolute havoc. Unfortunately for her, epidemics in Africa seems to peak in autumn and governments may already have become aware of their previous carelessness so hoping for a midwinter outbreak might be a far fetch.
We can always pray for an outbreak to northern hemisphere during the winter. Good luck Ebola-chan!