Title is very self explanatory, I was just wondering if it was possible with CFW or any other means with out factory reseting

As far as I'm aware, you can't downgrade Minecraft versions on any type of console. This is usually just a Java (MC launcher) feature.
I don't have a Wii myself but I'm pretty sure you can't. Hope this helps.

360, PS3, PS4, Wii U are able to downgrade through modding or emulation

is there a guide on how to do it on wii u?

I don't know if there exists a downgrading tutorial on youtube, but what I know is that you use Wii U USB Helper to download the game and install the version you want.

@TheUnknownMinecraftTheUnknownMinecraft
1. You can run any version of the game on Xbox 360 without modding.
PS3 can run almost any version if modded, but is easy to mod.
PS4 can run any LCE version released on PS4 but i believe it requires weird stuff including wiping ur hdd.
2. the wii isnt the same as the wii u cancelled + ratio

@spudpiggyspudpiggy My bad