It is rumored that you can access your FP+ via the
MDE app for your phone or by a centrally located kiosk for those wo a smart phone/data plan. So I think you'd be able, in theory, to make them day of but your point below is key...
I read somewhere
it will be 180 days and I think the point you are making here is what is freaking/stressing everyone out...
I hope so too. There is enough planning involved w/o having to decide what ride I want to go on at what time in what park 6 mos before I travel. I love planning, but that's a bit much for my taste.
My next trip isnt for another yr and a half so I am interested to see how it works out. Hopefully the impact will be realized by then and there will be manageable work arounds...we'll just have to wait and see...