Thank you!!
Yes, same here, my favorite walkaround lens is the 70-200, almost fixed at 200 :-D I love long lenses! Or very wide angles. Actually, Of the +10 years of professional wedding photography, I've shot 90% with two camera's, a 5D with the 17-40, and a 1D with a 70-200. And in very special occasions, I would go for a single camera setup, the 5D with 50 1.8 :-)
But indeed, like you say, with great lenses comes great instability :-) The IS on the RF800 is pretty good combined with the R5, so it is still usable, but I also carry a mono- or tripod as much as possible...