Quoted By:
I'm tired of this, i'm going to settle it RIGHT NOW
Jack and Rose COULD have fit on the door, however in that situation of panic and dismay, you arent logically thinking "hmm how can we get 2 on the door" your thinking "let me save you and i'll die". Even when Rose was ON the door at the ending we still saw she was probably moments away from death due to the freezing arctic waters plunging her body temp to dangerous levels. In cold water you can go hypothermic in seconds if your not prepared