I think I’d need to make sure that every room is tidy before your day off, so that you can actually clean. Otherwise your time will be spent tidying and sorting. Make sure there’s no mess, dishes, rubbish, laundry etc in any room by the evening before. Do jobs like cleaning windows and mirrors beforehand, as well as the skirting boards and doors.
On the actual day, I’d get up earlier than everyone else and put the washing on, then start with cleaning the fridge or oven if they need it (even better if you can do this on an evening beforehand). Catch up on ironing or recycling or getting ready for school. Wash any pets’ bedding and bowls etc.
Then when you’ve got the five hours to yourself, I’d open all the windows and go round with a bucket of soapy water with some dettol in, a Microfibres cloth to clean surfaces with and another to dry the surfaces with afterwards. Wipe mirrors and windows down with a dry cloth, change bedding and do the vacuuming/mopping. I take a carrier bag with me filled with cloths, wipes, bin liners etc so I don’t have to keep going downstairs for them and getting distracted.
Put rugs out for fresh air after vacuuming them. Wipe the stairs and banister with a damp cloth.
Put a podcast on as you go round and the five hours will fly - and get a take away so you can enjoy a clean kitchen that night!