Well you said this was out of the question, but Nava is free roam and she still has a cage to go into during the day when she wants to rest. She has a hay rack over her litter pan in her cage (she also has a second box outside of the cage) so she can poo while she eats her hay. She also has her food dish hanging over her box too.

Is your rabbit spayed? That may solve the peeing problem. You could try an even bigger litter box, or figure out a hay rack that you can put on the bathroom wall (maybe suction cups or sticky tack?) that won’t damage anything? You could suction cup the rack to the side of the bathtub and put the litter box next to it.

I just put my hay in the litter box. I buy it cheap enough, so a little waste isn’t a big deal.

try putting out smaller amounts, more often, so she eats what she has and doesn’t have the chance to pee on it before it’s gone and you give more

In his litter box and in a rack, not that he keeps it there though, lol.

I have a hay box that is peeled willow and she chews it as well as the litter, but it is pretty small – she can’t fit into it, and the sides are low. I set it right next to the litter pan so she can chew on litter and leap in to go when she needs to, but she’s trained already. You can try putting a cardboard toilet paper roll stuffed with hay into her litter box. She should pull on the hay but can’t stand on it. She’s ok to chew the roll. It would be temporary until she’s litter pan trained fully, but she can pull out the hay and munch while in there without ruining the hay itself. You need to refill it frequently to get her adequate hay, but it might break her of the habit of peeing on the hay.

My rabbits hay is in a cardboard box on the opposite side of their room from the litterbox, they won’t soil their hay so it can’t go in litterbox area lol

You could make a hay rack though out of a magazine rack and keep it in the bathroom if you wanted to try a hay rack.

I just put mine in the litterbox; bunnies will know not to eat if it’s soiled, and it gets all over the place as it is.  I’ve tried hay racks and such in the past, and really didn’t see much of a difference in terms of the mess (bunny would pull hay out of rack, or pull the whole hay rack down, and there’d be twice as much on the floor… so I went to just putting it in the litterbox itself.  Saves me some hassle.  Note I said “some” hassle. )

I have hay in the litter box, in willow baskets, in a pink plastic container. Before I leave for work, I always put new hay in