Peaches: Welcome to Bluelight. Before initiating a thread you would probably be better served by using the site's search engine since virtually anything anyone might hope to know vis a vis methadone has been discussed literally dozens of times. Indeed, your particular question was last initiated in late November and therefore is still alive and kicking in this very forum.
That said, since you did ask your question, and our esteemed Mods have allowed it to flourish, I will try to offer a bit of information; there are two seperate, yet interacting components to addiction, physical and psychological. With methadone, despite the old wives' tales, the physical withdrawal is relatively mild when compared to the gold standard in opiate/opioid addiction, morphine dependency (and for the record, technically speaking, heroin dependency IS morphine dependency). There is however a tradeoff in those relatively mild symptoms; while morphine dependency almost always concludes by the 72 hour mark, methadone's physical withdrawal will not even commence until approximately hour 96. This very long duration contributes to the inherent anxiety surrounding an impendimg withdrawal.
Psychologically of course, all bets are off. It is an entirely subjective dynanamic in which "Set and Setting" play the largest role.
As for your other question regarding the severity of withdrawal symptoms off of 1mg., in a nutshell, you wont experience any discernible PHYSICAL symptoms. In fact, if you have sufficiently plateued as you decreased your dosage, you shouldnt feel any discernible physical symptoms at 5mg., and precious little at 10mg.
Most people will disagree with what I have stated but do so on an entirely subjective basis. For the record, I have done three Cold Turkey withdrawals from 220mg and have nearly 25 years of using it on a more or less daily basis.