I’ve done poplar cuttings for a long time with very high success, you want a cutting roughly as thick as a man’s index finger, but dormant, with maybe an inch to a few inches of wood exposed. Fall plantings might be a little more successful than early spring, (more rooting), but it’s pretty close.
Willow is certainly easier to propagate, almost any stick should do, but should still be dormant, with lead time. Cuttings of willow placed in water should root just about any time.
Currant and related plants, gooseberry, elderberry, josta, will root from dormant twig cuttings very well.
I agree that mimicking the current energy system is likely a road to failure. The fossil fuel era was a golden age that you can exploit once every 60 million years or so. So sad that we blew that endowment in 150, and half of that since 1970. Shaft power still beats the heck out of muscle power, for when it’s really important…