Ethan doesn't want to face the bleakness of a New England winter by himself, so he impulsively proposes to Zeena to avoid that fate. Winter is traditionaly a season of cold isolation due to the weather conditions -- especially in the time period of this novel. Ethan wanted to move away from Starkfield and was busy pursuing a life away from the family farm when he came home to fulfill his duty as a son to his ailing mother. If it had been spring and Ethan could have easily travelled back to school for the following term and life would have been easier, he may have stayed only long enough to formulate his plan to leave again, but winter loomed long and he couldn't bear the thought of being alone. Once he is married to Zeena he gives up his dreams of college and pursuning a degree. He tries his best to eek out a meager existence on the failing farm and he patiently deals with Zeena's hypocondria. It is only when Mattie Silver comes to live with them that there is a light in his life again, but she is a dream that can't be achieved. Ethan can't bring himself to just leave Zeena with no means to support herself. After the failed suicide attempt and the crippling of Mattie and Ethan there is truly no hope that anything will change. The three of them live a quietly miserable existence in the broken down house and we see the truth of Mrs. Hale's observation that there is very little difference between the Frome's in the house and the Frome's in the graveyard. Ethan's not leaving in the winter of his mother's death is the seed of all the subsequent misery of these characters.