Non-ethanol vs 93

First and foremost go with the octane sufficient to prevent detonation.
If the engine is just being run out of gear, that's not going to be an issue.

Then after determining your engine's needs, if 0 E fuel is an option, then test it out.
Remember that there's different ways for a fuel to achieve an octane rating. All gasoline is a blend of hydrocarbons and there's all sorts of ways to tinker with the blend. The octane on the pump in the USA is a the Anti-Knock Index (AKI) which is simply the average of the Motor Octane and the Research Octane test results.

All of those different hydrocarbons have different evaporation rates. So its not like ethanol is the only component which evaporates easily. Every winter the fuel companies adjust the fuel mixture to make it easy for cars to start in cold weather and generally they don't use eth for that.

If the car is going to sit a while (weeks into months) then putting a high quality storage fuel into the lines and carb is a great idea. What I try to do is run the tank down, then fill with 4 - 5 gallons of storage fuel and run that long enough to get in the bowls. Depending on where the car is parked I might top off with pump fuel to reduce condensation. But in general I avoid having a full tank of winter fuel as Spring approaches. Had enough bad experiences with running winter fuel with its high Reid Vapor Pressure on hot days. Its not as bad with a closed evap system equiped vehicle but its something to be avoided. I've gone so far as to drain off fuel from the tank.

Final note: Your pump fuel is different that what I get around here. See the chart I reposted here
Comprehensive Test Regular vs Premium