Barry visits his father at his remote cabin and tells him about losing his powers to Zoom in episode 2x20 "Rupture".
The new Cicada takes Orlin to a remote cabin and reveals she is an older version of Grace in episode 5x16 "Failure is an Orphan". Orlin wakes up and leans that a future version of Grace has come back after taking up the Cicada mantle in the future in episode 5x17 "Time Bomb". Older Grace returns with the stolen device and checks in on her unconscious younger self in episode 5x19 "Snow Pack". Appears in 3 more episodes.
David and Mary Margaret escape the storm in a remote cabin in episode 1x10 "7:15 A.M.". Mr. Gold takes a kidnapped Moe French to his cabin to try and find his stolen heirloom in episode 1x12 "Skin Deep". Mr. Gold confronts August Booth about why he is in town in episode 1x19 "The Return".
Jack and Teal'c are relaxing on the dock when Teal'c receives a call from Daniel about the Goa'uld symbols in episode 4x13 "The Curse". Sam visits Jack to convince him to help them stop the Aschen in episode 4x16 "2010". From episode 6x15 "Paradise Lost". Appears in 1 more episode.
Ben offers his parents' cabin up to the newly arrived mermaids until they can return to the ocean in episode 2x01 "The Arrival". Maddie and Ben bring supplies to the mermaids and then try to come up with a plan on how to keep them safe for the duration in episode 2x02 "The Wolf at the Door". Deputy Staub comes by the cabin to ask about the ruckus at the gas station and sees the mermaid pack in episode 2x03 "Natural Order". Appears in 2 more episodes.