"... are against modern comforts of all kinds. ... Which if they're realistic is pre-18th."
Except they want all the comforts of that time too, which required a functioning civilization of millions of people to provide. And they had to be able to fit in and work within that civilisation and culture.
They can't fit in and work within any real functioning civilization.
What they want, but don't know it ,is to live essentially as a homeless person does today. An utterly minimal and miserable existence. They're welcome to it.