Most often, you'll have to live on base for PAT and any course. I know of a few guys who unofficially live off base. It'll be up to your CO but as long as you lived with your fiancée in Victoria before going to basic, there's probably no problem.
The wait times for QL3s differ for every trade and when courses are coming up, how many ppl are waiting for them etc. I'm recently posted to CFFS (CF Fleet School) and I'm waiting 5 months for my course to start. Again, it's all MOC specific but the next course available is already filled for me. And, depending on your trade, you may need security clearance before you can go on course. If this takes time, you won't be on course. I asked to go on other courses like NETP or language school but was told I couldn't for one reason or another. Also, you will rarely be posted to ship on PAT because you probably won`t have NETP, which is required. Depending on your trade, you can be posted to either coast for training. I know weapons tech is def east coast, nes, navcomm, nci, e tech etc are all west coast. If you go to Esquimalt, you'll live in Nellies Block with the others on or waiting for course. After your 3s, you can request to go to one coast or another, but they'll put you where they put you. Preference to coasts will go to those with families there. ie: you have a wife, kids and mortgage in Halifax, there`s a good chance you'll go back.
Like the other poster, BMQ is your first hurdle and trust me, you won't have time to worry about your next posting. Everything that happens in St. Jean is a game and the sooner you start playing it the easier it'll be. The indoctrination period will be the worst, but look forward to the small achievements like getting a new week number every friday and your first weekend off. Then look to Farnham and graduation. There's a lot of yelling, some days you'll never do anything fast, clean or good enough regardless of how hard you try. Do your best and realize that sometimes the staff just mess with you. Make sure you're fit before going in and be careful not to get injured. No matter how bad the day is, no one's going to remember tomorrow.