You probably could plant it as is. I would make it into a few smaller cuttings. But note you maybe get flowers on the outer tip growth sooner then you'd expect being from a mature tree.

Lucky you! Remember to not plant until the cutting(s) calluses well. The tree has water inside so it will not need much extra water until it starts to develop leaves as temps warm up. You can cut it up into smaller chunks, maybe 1-2' each and wait a week or thereabouts for calluses to form. Keep it in a bag in a closet and check it weekly or so. Then plant them when you see them starting to actively grow.

IMO the only issue with large cuttings is keeping them stable while rooting. If you can do that you have a very good chance of success. I would root as is (referring to the cutting size and not the condition of the cut end.)