3 midweek nights per week, every other week -

Hello, I live and work mostly remotely in Lisbon but my kids and my office and clients are in London so I travel there frequently. I am looking for a base where I can stay from Tuesday to Thursday in central London or near. In general, I visit every 2-3 weeks. Maximum 6 days per month. On the days I am in London I am ususally out at meetings all day and often dinners/meetings in the evening, but if not, I appreciate a quiet space and to just relax.
I am happy to pay up to £600-800 per month for a maximum of 6 days per month and to have a 'base'. Depending on location/facilities etc.
Occasionally my husband travels with me (once every two months so he would stay on occasion). We are both professionals, quiet and easy going. Love pets. I may need use of the washing machine for bedlinen/towels and to store my one suitcase in the room between trips.