Hi,

I didn't do it in one week, but in 10 days. Did all of the studying before
that and took the written on the morning of Day 1. If you've got all days
and a good CFI, it's doable.

The only thing to think about is: are you able to keep up with your rating?
If you do the IR in 10 days, you really have to keep flying and practising
IFR flying, or your skills will fade pretty fast. I started flying IFR right
after the rating with relatively high personal weather limits which I
lowered with growing confidence. After a long time without flying in the
soup, I'd never fly under minimum conditions - single pilot IFR is just too
dangerous to do it half-confident (well, all flying is, I guess ;-))

But do get the rating! It'll add a lot to your flying skills, you'll love
it!

Happy flying,
Patrick