Club member Dave Thorpe provided another idea for winter bumpers. Take some pipe insulation and electric tape. According to Dave "The lighter the bumper the less it sinks into the snow" also he says "They don't take on water like canvas".
Although not necessary for organized training days, filling out a DNR Permit for training dogs afield is a good idea. Especially if you are shooting / working with live birds. It's simple to fill out and is free of charge. Below is a link to the Minnesota DNR file. http://files.dnr.state.mn.us/rlp/permits/enforcement/dog_training.pdf