I guess if you're confident that all of the water lines are in places where a bit of heat will keep them from freezing, that's a perfectly good plan. I did a lot of designing in my TT to make sure that all compartments have good airflow. I used mesh fabric for panels and cabinet doors. I've insulated the floor fairly well and also the walls. I have a complete thermal break inside walls, floors, and ceilings , using foam insulation between interior paneling and the frame.
What I've found is that without fans to push heated air into those tight spaces, they will remain cold. October temps in Canada might not cause a freeze in those separate areas if a heater is used but I wouldn't be confident about that theory in the dead of Winter. I'm in MN, BTW.
