We have a single-storey pitched roof that falls down to gutters. The gutter
falls from right to left across the ~10m wide wall. At the left corner
there's a downpipe, a water butt connection, and then an angled piece of
drainpipe to take the water into an external kitchen drain that's roughly in
the middle of the wall.

I'm thinking of rejigging this so the gutters drain into a downpipe in the
middle that leads more-or-less directly towards the drain (well, slightly
offset to go around a window immediately above the drain).

Any pitfalls to expect doing this? Is there neat way to make a piece of
guttering fall in the opposite direction without drilling new holes in the
fascia for brackets slightly higher up? Can you maybe get brackets of
variable height or something?

Thanks
Theo