Depending on how low the temperatures go where the OP lives, the only option may be to warm the pipe in some way. In areas where temperatures get very low (less than 0° C), the pipe gets cold enough that the water can freeze when it comes in contact with the cold pipe. If this is what is happening, and it will could be in Ontario, no amount of additional draining is going to help! The only option is to keep the pipe warmer.
Installed a 6' self regulating pipe trace last night and wrapped it in 1/2" of preformed foam insulation. While the weather hasn't been as cold, the top area of the pipe that was about 0.5C before installation is now sitting at 4.5C.
Did some reading on the self regulating trace. Interesting how it can heat to different degrees along the entire run. Will look at other solution options in the spring but needed to know that the pipes were not going to freeze again this winter.