Supplies are really not an issue regardless of the difficulty setting.
There's such an abundance of them you'll never come even remotely close to run out.
Well, yes. But I also know tons of friends who were somehow unaware you could rest without using supplies, and as first-timers might be unaware that they're pretty abundant at all times. And sometimes, because of this design choice Larian has when it comes to long resting and triggering content, I have found myself needing to rest often to trigger scenes even though I have all or most my HP and spells, so there's no point in using those resources.
