As Congress decides whether to repeal a key provision of the Affordable Care Act, a Maine-based task force set to meet for the first time next week will be studying state-based fixes to the health care system. Included in the discussion would be long-shot proposals to establish a single-payer system in Maine. The Health Care Coverage Task Force – created by the Legislature after a hearing on a single-payer bill that failed earlier this year – will meet Wednesday in Augusta to begin a wide-ranging discussion on health care.