Covering an external door

Good morning.

I have an external wooden side garage door (framed, ledged and braced) which has some rot in various places. Generally thought the door is fairly sound. I am having difficulty finding a ready made repacement door due to it's non standard size (75 and a half inches tall, 24 inches wide, 2 inches thick). I have had a few quotes to have someone replace and fit the door but these have been outside of my budget.

Just wondering if anyone could advise f it would be possible to clad the external side of the door with something like a thin sheet of external plywood. If so, what would be the best way to attach it? Would it look odd though because the door would then be sticking out slightly further than the frame?

Many thanks.

If you want the cover to last forever, get 6mm or 9mm tricoya mdf (medite brand it 'extreme'). Fit with stainless pins.

Or some decrnt ply, but be aware the edges might weather. The best way to make it last is to round the edges with about a 3mm radius both sides all round before fitting and do same on door outer edges. Paint or stain both edges of plywood before fitting. Fit, fill and put on a final coat.

You will need head drip on top of door frame to protect.

If open in, put door drip on bottom to protect bottom of ply

Thanks Notch7, that is really helpful.

I am attaching a few photos now.

1) Do you think a sheet of, say 6mm external ply is the best/simplest way to go for a DIY job (rather than strips of cladding)?
2) Would it look odd if the door was then 6mm further out than the door frame?
3) There is also some rot on the bottom of one of the inside door verticals. Any thoughts on the best way to tackle that? Maybe I could cover the inside of the door with ply too, but I guess that would mean having to re-position the door?

Thanks again.

New door , 3 scaffold planks , about £30 ,