The two lodge guest couples "split up into groups" to go into the woods to find a Christmas tree. The first "group" (couple) to find one is to holler to the other group, and they're all supposed to cut down the tree together. So off they go into the woods, yet not one of the four has an axe or a saw or any other means of felling a tree.
When Chris changes the radio station, the actual dial he turns is for the air conditioning, but the radio audio still changes.
At about 13 1/2 minutes, the stock footage of the arrival in Rutland, Vermont, clearly shows a green Boeing 737 belonging to S7 Airlines (a Russian carrier based in Novosibirsk) in southern Siberia. As of late 2017, S7 doesn't fly to the U.S., nor could it from Russia with a 737.
When Molly and Chris are exiting the airport, the sign above the door reads 'Rutland Airport', as in Rutland, Vermont. But the sign on the door reads 'Tweed New Haven', as in New Haven, Connecticut.
The aircraft shown on the tarmac seems to be an Airbus A320 but when it is shown taxiing, and in flight, it is a much smaller aircraft, probably an Embraer ERJ145 even though its seating configuration is different to what is shown in the movie.
The overhead panel in the aircraft, when the crew call button is illuminated, shows seats D E F indicating a 3x3 seating configuration. However the interior cabin shots show a 1x1 seating configuration.
In addition, the text on the overhead panel is in German.