Don't know if I agree with more success from cuttings that have leaves. I propagate elm, maple, juniper, hawthorn, cotoneaster, and cherry hardwood cuttings taken in December, January, and February. All of these I can assure you are leafless and dormant. Out of about a hundred cuttings per species I run about a 80% success rate for the exception of the Junipers which run about 60%.
You may find that leaf reduction or at least leaf cutting will ensure a more successful out come. Brent Walston covers the subject in depth
here
One last note. You are pushing the limits of cuttings for this time of year. What you sniped of the tree would be considered a hardwood cutting and the success rate for that type of cutting is greater when they are in deep dormancy. So don't be disappointed if you find your cutting leafs and then wilts. Your next window of opportunity will be this May or June for softwood cuttings if you choose to pursue this........good luck