''Furthermore, not reducing our consumption and using nuclear (meaning now fission) for everyone would get us what? A century from now?''
there's a lot more nuclear fuel ,considering thorium , spent nuclear fuel, and seawater uranium, there are also breeder reactor that can create more fuel
''And there's no telling when/if fission will ever stop being "less than 50 years away".''
Maybe you meant fusion? but i would not wait for fusion to become a reality
'' Why not, but first let's lower our power consumption"'
you need 5 years to build a nuclear reactors but you can start immediately to reduce consumption,so i completely agree and i think we should do both