As for the "one in a lifetime" trip... take a laptop with you if possible. I find it much easier to judge which pic to delete and which to keep for further use on a bigger sized screen. Furthermore you have a hardisk to move your images to and can start with an empty memory card the next day which is nice too - just take some more shots! If I was you I would take some planned pictures ("must have" things) and then just fire away - bring back 300+ pics in the evening and dump the 150 that are out of focus, have bad light or where you are sure they don't make a big loss for you.
200 pics a day * 15 days = 3000 images! :shock:
If possible get you another rechargeable so you have a spare one in case the first runs out. Zooming and reviewing and photo composition needs energy...
Have a nice journey!
As for the resolution question... I don't use fine at all at my 4 mpix Oly C770. With 10x zoom you can compose the picture very well in most cases so you wont need heavy cropping. IF you'd need that cropping THEN it would be good to have as much detail as possible (i.e. dSLR with primer (fixed focus lens) 50mm or so trying to capture an object far away) but in your case - stay cool and use your zoom.