I ride a Milwaukee Beltline that is fitted with an Alfine 8 IGH. I ride year-round in Toronto. Last week, I noticed the wheel "dragging" a bit. I've never serviced the hub and have ridden it for 3 seasons, so I figured it probably needed a service. Watched a few youtube videos, and successfully removed the gearing from the shell. There appeared to be a tiny bit of water ingress (just a few drops here and there in the grease - maybe its just condensation??) but everything looks ok otherwise. Shimano servicing recommends oil bath with Shimano oil, but the internet has lots of opinions about that. So, looking for some more opinions. :-)

1. Should I degrease the full internals first? If I do that, do I just let the degreaser dry after swishing the hub around in the degreaser, or do I need to wash out the degreaser after (with water) and then leave it to dry? Rinsing with water seems contrary to keeping water out, and not sure it would ever fully dry from the tiny cracks and contact points.
2. As I'm riding in the winter up hear in the cold north, is there a recommended oil to use, instead of the Shimano oil, that won't be affected by the sub-zero (celsius) temperatures?
3. I've seen some suggestions to add a small amount (10cc or so) of oil to the hub shell before replacing the gears, and some that suggest adding the oil directly to the bearings and gears, and not pouring it into the hub. Or is just the oil bath (soak the whole thing, then leave to drip off excess) sufficient/best?

Seeking opinions of bike mechanics. Especially anyone who regularly services Shimano IGH (and better yet if they are located in cold climate).

Thanks.