Part depends on your personal shooting style, part depends on what gear you think you'll use while there, and part depends on getting it there.
As far as getting it there, one suggestion would be to put the 5Dc + 28 + 50 + 85 + flash + S95 in your carry on.
And then if you think you'll use it, and willing to take a bit of a risk, you could consider putting some or all of the rest of your less valuable gear wrapped up in a bunch of towels or clothes or even a soft padded camera case right in the middle of a big suitcase not containing any other hard objects, so that the suitcase effectively acts like a large well padded case. Depending on how many checked bags you are taking & how soft/hard their contents are, you could consider splitting your gear and putting one piece of your less valuable equipment padded in the middle of each suitcase, so that if by chance one particular bag takes a hard knock, all of your spare gear is not necessarily at risk.
Vistas you could take care of by stitching photos from your 28mm lens together, if necessary. You don't really have any telephoto coverage though, and a used 55-250mm lens is not a very valuable lens, so you may want to consider taking that, if you think you'll use it, even if you have to just pack it in a suitcase. If it does end up getting damaged, you could always pick up another used one fairly cheaply on craigslist or the like.
Or you could decide that the just the 5Dc + primes + flash is good enough for the majority of the better quality photos, with the S95 filling in when a more pocketable option is desired.