What is the external operating temperature range for a Crock-Pot or other slow cooker?
On the high side, it would be impossible for the pot to cool the contents below external temperatures, but most components (obvious weak point being the power cord insulation) will stand temperatures far above what humans will tolerate. The "classic" crock pot has no temperature-sensistive "smarts" to it, some of the more "modern" options might be more easily defeated than an old fashioned crockery/heating element/switch (possibly with thermostat, possibly not, in neither case "smart") / insulation/shell construction.

On the low side, there will eventually be a point where the power input on low won't keep the temperature above 140°F due to the level of insulation and wattage of the elements. Anecdotally, many long-boiled things were boiled (probably on high, not low) in our unheated shed to keep them out of the heated kitchen at temperatures ranging down to 0°F (no wind, being inside) and they boiled. Less anecdotally, you could run experiments with a crock-pot and water and a thermometer to see what that specific unit could do at a specific outside temperature, but it would only be valid for that specific unit.