Cynthia Littleton Business EditorMagnolia Network opened its doors on Jan. 5 to an audience of about 3 million viewers, powered by the linear launch of “Fixer Upper: Welcome Home,” the renovation series hosted by Magnolia chiefs Chip and Joanna Gaines.Magnolia Network’s first night of primetime programming garnered about 3 million viewers in Nielsen’s L3 ratings. The lifestyle and how-to channel marks the return to TV for the Gaines, who have partnered with Discovery in the streaming and linear launch of the curated Magnolia Network as a streaming label on Discovery Plus and the linear channel as a rebrand of Discovery’s erstwhile DIY channel.The linear debut of “Fixer Upper: Welcome Home” on Jan.