I have an ENT tool specifically designed for this situation when the parents bring their kid to the ER with something stuck up their nose or ear. If I was local to you, I'd offer to come over and try to pull it out.
If it really is too far for your home tweezers to reach, I'd caution against waiting a few days for it to work its way out. The reason is that your nasal passages are not epithelial tissue, like skin, but rather mucosal tissue which can break down quite easily if a foreign object is pressing against it for a few days. If your son is calm, you can probably let him sleep and see what happens overnight. It'll either come out, get swallowed and eventually passed, or stay in there. Then tomorrow, if it's still up there, take him to get it pulled out. Most urgent cares will probably not have a suitable tool besides standard tweezers. A pediatrician office may, and an ER that regularly sees kids should. Good luck.