Interesting.
Most houses in the UK have the main bathroom upstairs. Although there are cultural differences. Areas where downstairs bathrooms are more traditional. I understand these aren't very popular nowadays with house buyers, who can be put off by a bathroom downstairs enough not to buy or who make the ability to shift the bathroom upstairs a necessity of buying.
Ours is upstairs and at the end of a short hallway to the left.
Many houses in the UK have a small 'downstairs loo' as an addition. Just a loo and handbasin. Or just a shower or wetroom. No bath. In the case of older houses, a downstairs room or cupboard is often converted to provide this. These are very often next to the front door.
More than one house in our street has had the downstairs cellar converted in this way. It's right next to the front door. Though it's not at all what you guys in the US would call a cellar, I'm sure. It's really just a very small room. But big enough for the purpose.
LabRat
