Well, welcome to the 'High ISO' Club John, not even some folk with 1DXMKII venture this high.
As, Bill said, nice alert pose, however, are you standing or kneeling, I still feel you need to be lower. I assume you have used the centre FP here judging on the FF image posted which will offer the best 'sharpness' rather than using other FP's, but don't be afraid to use them. I think you can afford again to go tighter (not a problem with the 5D4), but also get some depth back into the grass too.
You should be well chuffed in getting this and the camera didn't explode, melt, cause issues after shooting this high, well now you know you can put things when you need too.