300 vs 100? Hardly, but, you're right in that the adjustment would be tough for those who like warm weather. I spent the first 42 years of my life in NY and the past 11 in NC. When I talk to people down here, the number one reason they never want to move back north is due to the cold...though I don't recall the number of days the sun is shining being in any conversation.
As for why those two guys are transferring or transferred, sometimes people are just followers. Kelvin Sampson lost his entire 2003 recruiting class (except his son who walked on) to transfer. I'm not sure how either that situation or the one in Columbus played out with two leaving/left so far, but guessing weather was not the primary factor.