I am a very healthy 67, so I plan to continue trips long after 70 but will probably shift to landscapes, etc. At a minimum, I will scale back from the heavier professional lenses and gear. My typical gear for a hard core wildlife trip is 1dx II, 5dIV, 24-70 f2.8 L II, 100-400 f4.5-5.6 L IS II, 200-400 f4 L IS w/1.4x tc, multiple batteries for both cameras, battery chargers, binoculars, RRS Tripod & Wimberley Head (not for Africa), 1.4x & 2x TC III's, etc. I like the 100-400 II on my backup camera when I need to shift to handheld shooting. This was the bag on my 2017 Africa trip where I was doing Gorillas and wanted the 100-400 II for the mountain treks.What do you carry for gear? I hope the rest of your trips go well...I'm betting the last few minutes of your final trip will feel quite poignant after however many decades you spent out there photographing wildlife.