I live in Regina but i visit saskatoon very often because i have friends there. I personally like saskatoon a little bit better than regina but my wife, for example, likes regina better. Both cities are very similar it is just that in my opinion saskatoon seems to be a younger city than regina.
I think that both cities are excellent to raise a family. I have two small children, one of them in grade 2, and our experience in that area has been great so far.
About jobs... i think that if you have an occupation in demand (you should if you are in this forum) and you have good english skills you will not have any issues finding a good job. Remember, you know you have something to offer to employers, you are a professional. You just have to show them your skills and you will be on your way.
In my case i was hired at my first job interview and they were not even looking to hire anyone at the moment... they just saw that i had something to offer and they made room for me. I know that this may not apply to all companies or all careers but i am speaking out of my experience. I am a mechanical engineer and i work in the refrigeracion and HVAC industry.
The cold? well... today was -34 celsius with the windchill... if you work outside or if you do not have a car it can be very challenging for sure. In my case i have a car and i work indoors. I just dress for the weather and everything is just fine.