Thank you for the replies. I'm sorry its been asked relatively recently, Ive been busy and inactive on here for a while, just lurking occasionally. I am definitely hopeful that a 5DSR II would have everything I'm looking for.
A 5DSRII would hopefully have more than just a m-pix benefit over a 5DIV. I'm optimistic that it would also have a flippy screen like the 6DII and no anti-alias filter. I'd prefer these features over the slight fps and buffer advantage of the 5DIV (Im assuming the MKII would improve over the previous in these regards too).
I do most of my shooting when hiking or traveling and I shoot mostly landscape and wildlife (often birds). Right now the options of 5DSR, 5DIV and 6DII all have pretty big trade offs, none quite as all round as I'd prefer, a tough choice.