Internet, mobile & electricity

Are eSIMs available in Greenland? Can I buy a local SIM card? Do I need a power adapter in Greenland? Does EU roaming apply in Greenland? Is internet access expensive? Is there mobile phone coverage in Greenland? Is there Wi-Fi in Greenland? What power plugs are used in Greenland? What voltage is used in Greenland? Will my phone work in Greenland?