I also have N scale on a patio table. Here in Northern California winters are a little more severe then down south but I have had little trouble. The biggest problem is dust from nearby construction. Care must be given to the type of track used as some will corrode very quickly and be almost impossible to clean. Also don't put in any tunnels unless you have a way to clean inside them.
Most rolling stock will not stand up to sitting in direct sunlight as the plastic quickly softens and warps into unrecognizeable shapes. And please don't ask how I know!
I still prefer my G gauge in the garden.

Happy RailRoading
Doug

Everyone has their preferance and we want the manufactures to build what we want. The reality is that Bachmann will build what most people will buy, not what a small group insists upon having. Any one group of railroaders, weather they are into DCC, battery, DC or RC is a minority and we all must make a buying decision based on what fits our needs best.
If Bachmann makes something that you don't want or can't use then don't buy it. But don't be mad because it wasn't built to your specs. My buying decisions are made by looking at a model and seeing if it can be modified to work for me.

Just my thoughts on the subject
Doug Dodd