I asked a similar question in a different forum prior to a one-month 9000km motorbike trip through Patagonia. I proposed to carry similar (Canon) gear to you. Some of the old hands replied "You're taking way too much gear". I thought "Phooey!".
They were right!
I have just bought a Canon G10 that would have been a far better choice for my trip and I suspect yours.
Weight is one factor, bulk is another. Concern about damaging the camera gear while travelling and yourself if you fall off while carrying some much on your back are also important. But the final point is that a point and shoot is much, much more convenient. Put it in a fanny pack and it is available for those spontaneous shots at a moments notice. In a car, you can leave a DSLR with attached lens on the seat beside you - you can't on a bike.
I also took an old Canon A75. Just about the only times I used the DSLR was when I had dedicated photo events on the trip - it was simply too much hassle, even though the quality of DSLR photos are (of course) vastly superior. And on a motorbike I had much better load carrying options.
You might also check with your wife if its okay to fill your load carrying capacity with camera gear!
I have yet to test the G10, but my exectations are that at low ISOs it will provide acceptable, probably even publishable, photos. Oh how I wish I had it in Patagonia last November!