An interesting one, for travel shooters. I think everyone is going closely over this question: 'what do you really get for YOUR work in making the change?' In pure image quality terms, less than might be made up in other ways. I feel this closeness is there in IQ at base ISO, as the generally reliable DxO sensor tests indicate the only real gains (as in noticeable gains) come in the bulge from ISO 800-1600 upwards, and even then only in DR.
http://www.dxomark.com/Cameras/Compare/Side-by-side/Sony-A7R-versus-Sony-A7R-II___917_1035
If you are happy enough with output resolution from the 36mp item, it moves to the gains in operational and build factors. No one disputes these very real gains which will result in better h/held output, the reviews and owner reports have plenty, so no need to go over this ground.
So let's look at the other side. How do you feel about carrying a $3200 body as the only body, with no backup? Even taking a backup is many dollars extra tied up, and if your economy is souring many are unable to do it. I love the idea of extra bodies for travel, even though my Sonys are ever reliable, so two a7r bodies enters the picture with less risk capital for that slip or slosh moment. And your two favorite lenses each with no/minimal exposure to the elements from lens changes is just a great thing to have, if each fits in a small bag. This line of reasoning applies purely to shooters who work around the 'issues' of the a7r with little consternation - we all differ here.
Lastly, opportunity costs - the things you can do with the money if you settle for the now stale (and effectively discredited, and therefore cheaper!) a7r. It might be around $2000 or so, more in non-US regions. That is a lot of state of the art lenses and the capabilities they bring to the table to improve the final results. The two Batis lenses are a little under-priced compared with alternatives, and are far better for usability and overall versatility/quality of output, somewhat weather sealed too.
If we factor in even a half stop extra from OIS in either Batis 85 or 90 macro, it goes some way to helping in low light. These lenses will hold value very strongly. So the 'head' rather than 'heart' might argue going that way, perhaps with different lenses to suit you. My dad used to say that a real good older car is best because 'it doesn't owe you anything'. I doubt may FE users will not get an a7rII someday, but the exact day that happens might vary due to other ways to manage your 'spend'. cheers, and have a great trip!
'In an age of multiple and massive innovations, obsolescence becomes the major obsession. '
- Marshall McLuhan