If you can move to Bend with a job that can get you by on one income, then do it. It's an awesome place for us outdoorsy types, but I imagine the job market is pretty similar to South Lake. Your fiance might have a hard time finding work if she needs to.
Otherwise, I'd say stay put. Yes, family is far away, but you already have a community and circle of friends who can help. Keep your jobs until you finish school, and keep your eyes open for survey work.
In the next year, your perspective on EVERYTHING will change more than you can imagine. After the baby comes (plus a few months of sleep deprivation), you will probably find that the path into the future becomes much clearer.