Lyric discussion by Dayrader 

Cover art for River lyrics by Sarah McLachlan

These are not my thoughts, but i think the same as Michael Ball, a British stage actor and singer:

"It's coming on Christmas, they're cutting down trees/They're putting up reindeer, singing songs of joy and peace." Ultimately, it's a bereft song about a woman whose romance has gone bad and who wants to escape. The drama just happens to be set around the holidays."

Song Meaning