Okay I'll just summarize everything here so that it answers all the questions:
1. Off-Campus Housing: You can easily get an off-campus place to live in at walking distance from MUN for around 400 CAD a month. Plus, even if you live a bit far from the university, the metro-bus routes here touch the University so you can take the bus. Its not that expensive at all. (I really dont think you will have a problem with respect to off-campus housing. Even the university website itself has off-campus living advertisements placed) And you can contact the International Student Office too for any difficulty. So that wont be a problem.
2. Climate: Well, its rated as the 2nd mildest city in Canada as far as climate is concerned
(But Hold On!)! The weather here changes pretty often, you can sleep one night with a clear sky and wake up in the morning and look out the window to see everything covered in snow.
But you get used to it eventually. And once you start spending time here, its fun to see the weather change so drastically.
3. Living Conditions: The living conditions are pretty good. Its a clean city with everything not too far. You can easily purchase stuff that you walk at walking distances. For Muslims, there is a Mosque and they have a bus that goes to the mosque from the university every friday for the prayers. Moreover, there is no issue of practicing your religion. They have a designated prayer room in the University too. And you can see flyers of various seminars of different religious topics from different societies. So its a pretty balanced life here and you wont have any issues. The attitude of the people here is by far the best I've seen. They are down right humble, friendly and you wont feel anything such as a racist comment or something.