@David6152 Stays longer than a weekend aren't considered "long term". Long -term usually refers to a month or more.
Most of my guests stay a week or two (2 weeks is my maximum I accept). My guests get 2 bath towels, a hand towel and a washcloth, and clean bedding, of course. I offer fresh towels and sheets after a week if they are staying for about 2 weeks, if they are staying 10 days, I'd offer that halfway through their stay, at 5 days.
Many say they don't need clean stuff- especially the sheets, but most usually accept clean towels.
I don't charge any extra fee for this- I just charge enough nightly fee to cover this. I don't think it's a great idea to charge for clean linens- I think it's something guests should rightfully expect when they book an accommodation, but some hosts do it differently.