It would be difficult for any of us to give you any idea without seeing the job. With experience you'll know how long a job should take, so take a good look around and picture in your mind how long each session will take, multiply by your hourly rate and submit as an end price only, don't go with some first 'x' metres at £? and the rest at £?.
As a goldern rule never quote on something of this size without seeing what you will be up against. Also it's worth putting on the quote that the price is based on the condition of the carpet as seen at the time of quotation, this stops painters etc saying sod the dust sheets the cleaners will go behind us.