The song that Ellie sings when she, Aaron, Grant and Gretchen are sitting around a camp fire is 'Under The Milkyway' by The Church. It was a single from their 1988 album 'Starfish'.
The film was shot in late 2018 and was originally supposed to release on New Year's Day 2020.
Most characters pronounce Grant's name with a short 'a' sound (rhyming with any) , but at the funeral, Gretchen pronounces it with a long 'ah' sound, characteristic of a South Australian accent, suggesting her character may have originally been from somewhere else.