Summer stay with potential extension

I am from New York and am in London for an extended period for business (I work in private equity) potentially through the rest of 2026. I am looking for a place to stay during this time. I'm generally quite flexible and easy going and won't be in the flat much.

Have a strong preference for a full flat (studio or 1 bed) in west and central London. Ideally in a nicer building (must have washer in unit), but does not necessarily need to be a luxury building or new. Budget is somewhat flexible depending on the situation.

I am already in London and can meet in person. Ideally we can be month to month with flexibility to extend.

Do not smoke nor have pets.

Thank you.