I've so far found Nova (on the Moto Z series of phones) to be ok if:
I don't try to squeeze too many lines and columns on a screen, so that there's enough space between icons regardless of orientation, even though that means wasting some space
I add more screens instead of letting a screen become too crowded
I'm very selective in what widgets I add – there are some which work well enough for both orientations, too, like a weather app I use or my preferred calendar app (DigiCal)
I'd prefer a "better" solution, too, but every other launcher I've tested so far has some other