Rivnuts from Homestead. PA on 7/3/2019 6:46:20 AM:
December is not the ideal time to ride the C&O Canal Towpath. As you questioned the temperature can be cold with highs in the 40's (F) and lows in the 30's with extremes beyond that. Rain and snow could be encountered as well. Camping would be uncomfortable and the wells at the hiker/biker camp sites would not likely be operational.
While you did not mention riding the GAP Trail, note the Big Savage Tunnel would likely be closed at that time as well.
In summary, I'd lobby the conference sponsors to reschedule the conference to late spring or summer. ??