You'd be wise to wait... can see the line ultimately moving to Denver -4.5ish in the end. The Broncos are a huge public team to begin with, and in a situation like this, for the NFL Championship and with the line so low for a typical Broncos game, you can expect a huuge majority to keep pounding them leading up to the game - while it remains this low.
There's two weeks between now and then. Hell, those Vegas scumbags moved tonight's Pelicans/Grizzlies Under from 191.5 to 187.5 in only a few HOURS (Thus costing me a much bigger victory if I was to catch it at 192, with the extra half-point, so did for much less on 188 ughh), and in a matchup like this with two weeks to ponder, movement seems inevitable.