For me, 19-27 September is being kept free for 4 x audaxes. I should be able to work them around normal work/family life, so I will put together a conservative plan and calculate the sleep/work balance!
Riding to Wales and back might be a bit ambitious, given my mileage is way down on recent years, though in early May 2018 I rode my 'Grand' DIY, not really expecting to be fit and fast enough to get round in under 75 hours. The main aim was to check the route, so I could always revert to touring mode. As it turned out I had rather less sleep than plannned, but got round comfortably enough with hours in hand. The weather was kind though, with light winds, mild nights and nothing like as hot as it got later in the year!