You have to pick:

Wait, is running 1 mile in 8 minutes even that hard? I've run 2 miles in 11:30, and I'm not runner (granted, I am a sprinter)

So...essentially, you have 41 days to walk 1,000 miles..
...which is about 24 miles a day...
Hmmmmmm would it be worth it?

If you are a runner it will be easy. If you are in good shape it will definitely doable. If you are in average shape it will be hard, but likely doable if your life depends on it. If you are in bad shape it will probably be impossible.