I saw an article about this change yesterday and thankfully our car will take the new E10 fuel.
We have always kept the tank topped up but once the E5 is no longer available we will have to keep our fuel reserve a lot lower as, only doing about 5,000 a year tops, we will presumably have to guard against the fuel in our tank deteriorating.
Ah well I guess this will result in our spending more time in my portable bubble. <sigh>
I will certainly be looking into mrmistoffelees's suggestion about a fuel stabiliser so thank you Mr M.