Slides that have sinks, washers, whatever that require water also require hoses. Normally, these hoses will slide back and forth in top of cargo area, or in bottom of cabinet.
On the bottom of slide itself, there is usually a "slot" opening for hoses to move around / through. Slot is protected by a "brush" seal.
It is VERY easy to put a low wattage lamp / hose heaters / pipe blanket in this area and get power to it (if required).
Behind the appliances, inside cabinets, etc you can slide on split-length foam insulation. Heck, do it to all accessible pipes, not just slide.
I wouldn't worry about freezing being the deal breaker. But, do plan on some additional self-work to prep as you want it.