One man decided to go out for Da'wah (Jama'ah Tabligh) for of Allah for 4/5 days or more. When the day came for going out as per his preparation, just 3/4 hours before his wife got very sick (was an emergency sickness). The man went to doctor and tried his best for her relieve but he could not meet with doctor. In this way his time was going out because he has to catch the transport and he had some other responsibility for the Jama'ah.
So he gave up his trying for his wife's treatment and he left her in home alone for Da'wah. When he came back he found his family absolutely well and good. Asked his wife, what happened to her after he left, said she was about to die, suddenly she got a dream or sound to use one medicine, which was available in her home; she used that and got relief.
Now my question: In that situation is it permissible for that man to go out for Da'wah, and does he and his family receive a good reward from Allah (like Jihad in battle field)?

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

If there was nobody to look after his wife during her critical illness, then he should have stayed with her to treat her and it was unlawful for him to travel and leave her in that state. Al-Bukhari reported that the Prophet permitted Uthman not to participate in the Battle of Badr in order to treat his wife (the daughter of the Prophet, sallallaahu alayhi wa sllam. He said to him: “You have the reward of a man who participated in Badr and you will be given the share of a fighter from the booty”. (In the narration of At-Thirmithi the Prophet ordered Uthman to stay with her and she was sick). So, if the man was ordered to stay behind in Jihad in order to look after his wife and treat her, then it is more emphatic to order him not to leave his wife for Tablighi Jama'ah or anyone else if his wife is seriously ill and there is nobody else to take care of her and there is possibility for him to make Dawa'h without leaving his wife in such a critical state. Allah Says (interpretation of meaning): {…And live with them honourably…} [Quran 4: 19]. And it is not kind that the man goes out and leaves his wife very ill without providing her with the necessary assistance. We would like to draw the attention of the dear brother that it is impossible to leave Shariah rulings which are clearly stated in Qur'an and Sunnah just for the sake of some dreams or other things that happen to people.

Allah knows best.