It depends on growing conditions, but if they're favorable, I'd allow eight feet or more. Perhaps four feet if the plant is starved and oppressed.

P.S. I changed this; for some reason instead of 'Louise Odier' I read 'Mrs. B. R. Cant', who knows why. Louise will spread quite wide if given the chance, even when pruned to keep her shrubby.

I wrapped mine around an obelisk, so I cannot tell you how wide it would be if grown free standing. I suspect it would be floppy and quite wide.

What I can tell you is that it throws up a lot of long but short lived canes from the base. In my garden, every cane turned yellow and died after 12-18 months. It also suckers mildly if it is on its own roots. It was a lovely rose at the spring flush, and less lovely later due to PM. It repeated somewhat after a few years in the ground, but not heavily.

I grew it for about a dozen years. When I decided to reduce the number of roses in my garden, it was one of the ones I removed.

Rosefolly

When we grew it, it grew to the top of our retaining wall -- 12-14 feet ... But like Rosefolly, we found that for us it had many long, but-short-lived canes, and like her, we found it to be troubled by uncontrollable mildew. So, as you might guess, it is long-gone.
In different conditions, where it didn't mildew, it might be fine.