When it’s just you and baby in public, but you’ve got to pee

I’ve got two questions here that are kind of the same and I’ve been wondering for months what other women do in these scenarios, so I’ve decided to ask the other moms (or dad’s) on here:

A) say you’re at a fair/festival and it’s just you and baby in the stroller. But you’ve got to pee. Your options are a porta potty (stroller won’t fit), or a couple stores/cafe type things where you can’t get the stroller inside because there’s stairs (or the stroller won’t fit in their bathroom either.

And the other:

B) you’re somewhere in public - let’s say a grocery store. You’ve got to pee but you don’t have anything to set baby down in (the cart won’t fit in the bathroom and baby has outgrown the infant car seat, but baby can’t stand alone yet). Do you go to the bathroom in a public stall while holding your baby at the same time? How do you undo and redo your belt? What if you hover a how can you see? What if baby wants to touch everything? How do you manage?

BTW: my baby just turned one so she’s a bit heavy to babywear for long periods, and I’m not sure a sling would work for her age/size.