My other half and I took advantage of this offer when we were looking for a cottage recently.
Due to the late season, this agency have loads of cottages available for couples from £99 upwards for four nights.
The direct link has a link to the cottages so you can have a browse but you have to call them to find availability. I'm not sure the changeover day really matters because we started our four nights on a Thursday for a Saturday changeover cottage.
So decide on your dates, call them and they should give you a list of reference numbers to check on the website.
Good holidays!! We stayed in Willowcot cottage and it was truly lovely.