Yeah, I'm with Laurel -- if the smoke is coming out the scoop it's probably not a dying turbo. I'd expect failing turbo seals to toss oil into the intake airstream, causing smoke at the tailpipe rather than out the chimney. Is the turbo louder than normal?
Actually, smoke from any part of the engine bay can find its way out the hood scoop. When my valve cover gaskets on my 97 Legacy GT were leaky the scoop would smoke at stoplights.
It could also be one of the oil lines on the turbo. If it's the feed line, the copper gaskets are pretty easy to replace. Valve cover gaskets are pretty easy too.
So, yeah, degreasing the engine bay and then seeing where the oil appears sounds like a good idea.
I don't want to give you bad advice, so realize that this is a completely unprofessional opinion, but it seems to me that if you can stand the smoke and if you check the oil level often, this shouldn't be a show-stopper for your 3000-mile trip. Of course, it'd be way better for everyone if you could fix it before leaving.