Just know that when you take the water out of a hot tub for extended time the air gets at everything. Seals around jets deteriorate, Metal (heater element) will rust. If you take the water out and keep the cover on it will get real damp and moist under there with outside temp changes and mold will grow. It will be even worse if you use RV anti freeze. If you have to winterize you have to suck and blow out every line open all the pumps and get ALL the water out from every orifice in the spa. Any water you can't get out will freeze, expand and crack plumbing. Spas that use one way check valves in the main plumbing often get missed as you have to remove the water from both sides of the check valve. Make sure to spray the interior shell with a mold inhibitor spray.
