I'm in zone 5, so not too different from your zone. If you kept your plants in an unheated garage and did not water them, then you would likely be able to work with them. However, the plants will not be as nice as if they were left outdoors. If you water them or expose to heat, then they will try to grow and would etoliate badly inside. If kept cold and dry, they remain essentially dormant. Note that too dry is also not good, hence the garage. I have overwintered strawberry jars with semps in our unheated garage many time without problems. They sit on the cold garage floor and are ignored until put back outside in the spring.
Greg and Lynn gave good advice. What you want to do is possible in your climate, but difficult.
OK to plant the log, but I would not delay. Make sure that they get snow cover which will protect from drying winds.
