As had been expected, filming started back in October 2017. We got some more concrete information on this front when a number of actors begun arriving in Belfast, with a table read taking place too.
The likes of Kit Harington, Emilia Clarke, Nikolaj Coster-Waldau and most were spotted too, including one actor whose return could be considered a spoiler.
As for its ending, The Hollywood Reporter notes that it could run until August 2018, which makes it one hell of a long shoot. For comparison, Season 7 started filming at the beginning of September, and finished early in February, so filming Season 8 could take twice as long. Iain Glen offered some clarification on why this is, as he said that since everyone is together, it means they only have one filming unit rather than the usual two (via Watchers on the Wall).
That means we're not going to see it until 2019, which HBO's programming president Casey Bloys had previously suggested and the network has now officially confirmed. Season 7 aired five months after filming wrapped, and with Season 8 even bigger in scale it could take longer - a return to its old April slot, or another summer outing (given the ratings success) could be likely for 2019.