Janet gave you all the answers except one.

ALL of my main plumbing from the drains to the pump, to the filter, to the returns is plumbed with removable PVC pipe, some hard, some TigerFlex. By plugging all the drains and returns I can remove ALL the plumbing, drain it, and store in my basement. I only have to worry about blowing out my solar panels, and the bridge hosing between them.

(Each solar panel is 2'x4' and I have 30 of them surrounding a 16'x40' pool. They are connected to each other by 18" long bridge hoses. 15 panels feed one warm-water return and the other 15 feed another, so I can turn them on depending on which group is in the sun.)