What is the ruling on sharing accommodation and eating with a person who drinks alcohol when one is unable to change residences?

It is obligatory for you to advise your relative who drinks alcohol to quit, and to explain that it is among the major sins, and that drinking it incurs Allah's wrath and punishment. The proof for this is the Almighty's saying: "O you who have believed, indeed intoxicants, gambling, [sacrificing on] stone altars [to other than Allah], and divining arrows are but defilement from the work of Satan, so avoid it that you may succeed. Satan only wants to cause animosity and hatred between you through intoxicants and gambling and to avert you from the remembrance of Allah and from prayer. So will you not desist?" [Quran 5:90-91]. And the saying of the Prophet, peace and blessings be upon him: "Every intoxicant is forbidden. Indeed, Allah has promised that whoever drinks intoxicants, He will make him drink from 'Teenat al-Khabal.'" They asked, "O Messenger of Allah, what is 'Teenat al-Khabal'?" He said, "The sweat of the people of Hell or the pus of the people of Hell."

If he does not desist, then shun him to pressure him until he stops drinking alcohol. There is no harm in using his utensils like cups and plates unless you see the alcohol itself on them. Likewise, his eating and drinking with you is not forbidden.

Know that residing in lands of disbelief is permissible if a Muslim can establish the rituals and is safe from temptation; otherwise, it is obligatory for him to migrate to Muslim lands.