Don't forget increased efficiency can lead to more total collapse and not less if not managed correctly. The way to see this is that being more energy resource efficient effectively results in the cost of energy per unit of work declining. Reduced costs make the less economically viable sources more viable so when the final collapse does eventually happen you are left with even less than had you persisted with less efficient means.

For example, a fisherman who only has a big net so can only catch a certain number of fish. If fish populations drop sufficiently then he will go out of business. However, if he manages to develop radar technology and other gadgets to track fish more easily he can go further out and catch more fish. His business remains viable for longer but if he persists long enough even that resource will be exhausted and now the total fish stock will be further depleted than if he just kept with the net. This is the danger with increased efficiency if you fail to consider the broader picture.