The snowed-in cabin is the purest version of the forced-proximity trope. No signal, no road out, no third person, and a very good physical reason to stay close to each other.
Everything the scene needs is supplied by the weather.
The situation you walk into
A remote cabin, snowed in for the night. The storm has taken the power out, there is no signal, and the only warm place left is the rug in front of the fire. There is one blanket.
You are the other person stranded here. She is the one snowed in with you, down to sharing the firelight.
Choose who is stranded with you
The storm does not care who is in the cabin. You might.
Why isolation is the strongest setup
Most tension in a scene has to be manufactured. Here it is structural: you cannot leave, nobody is coming, and warmth is a limited resource that has to be shared. Nothing needs to be forced, because the situation is already doing it.
Cozy rather than desperate. It burns slowly on purpose.
Build who is by the fire
If you have someone particular in mind, create the character first and the storm will be waiting outside.
