Probably the cheapest and best option is to build more wind and not care too much if it increases curtailment.
Yes, all the things mentioned should be looked into and done when it makes financial sense but "wasting wind" is much less a thing to worry about than "burning gas", and I'd rather waste wind than waste money.
The incremental cost of keeping a gas generator working is very close to zero compared to all the other expenses involved in building the plant and buying gas to burn in it. We can keep all our gas infrastructure around and simply use it less often if we have more wind.