For wildlife photography I use Nikon D4 camera and a Nikon 400MM F/2.8G ED VR Lens, then I have TC 1.4 and 2xTC. This combo it give me a lot opportunities. Of course, it all depends on the light you have available. Mount it on Gitzo tripod.
For landscapes, I use Nikon D800 and with a Nikkor 16-35mm zoom lens and for long expose photos, I add LEE filters to the lens. Mounted on a manfrotto tripod and a wired remote controller to the camera and you are good to go.
For me it is important to practise my skills, and about upgrading my Photo gear is somehow, secondary. There is coming a lot of new products all the time on the market, and for sure I also believed it is better (compared to what I use today), like focus points, tracking, etc.. But again, I if you can handled different techniques, you are indeed in upfront when you upgrading your camera.
Just my thoughts.