Map of Westeros during Season 8 of Game of Thrones. I did it in like 20 minutes so if there are any errors, sorry. I couldn't find any information for what happened in the Reach, the Stormlands and the Riverlands after Season 7, so I guessed. A LOT.
In the Riverlands, Edmure Tully managed to escape from the grip of the Lannister forces in the south and later lead a short-lived insurgency which did manage to cause considerable chaos for the Lannister forces garrisoned there. With House Frey wiped out, the local lords in the northern Riverlands are just keeping their head low and hoping they survive another day. The Northern and Vale forces have occupied small areas to link up their forces along the Kingsroad.
In the Stormlands, Lannister forces have a very considerable presence, after House Baratheon was wiped out. Not much else is happening here.
In the Reach, Lannister forces occupy the northern areas so they can control the Gold Road, a strategically important road going from Casterly Rock to King's Landing. Some surviving Tarly bannermen reside at Horn Hill and still pledge for Cersei. After the Sack of Highgarden, the Reach has devolved into dozens of political squabbles, with assassinations being very common nowadays.
In Dorne, Quentyn Martell (who I assumed was the unnamed Martell in Episode 6) has taken power after the death of Ellaria Sand and her daughters (only good writing decision since Season 6) and has pledged Dorne to the Targaryens, according to Varys.
In the Iron Islands, Yara essentially just landed 3 ships on the Islands and all of Euron's forces there defected to Yara's side, according to Varys.
In the North, the Army of the Dead continues their march southwards, after the Fall of Eastwatch and Massacre at Last Hearth. They are about 30 or so miles north of Winterfell, where all the Northern, Vale, and Targaryen forces are waiting for them to come. All settlements north of the Last River have been abandoned, with massive refugee movements towards White Harbor and the vacant Dreadfort. The Night's Watch and Wildings are also going to abandon the Wall, as it is essentially useless after Eastwatch was destroyed. Castle Black and Shadow Tower are only manned by 60 men each, with the remaining 600 men and 1000 Wildings falling back to Winterfell.
In the Vale, nothing is happening. At all. Same with the Crownlands, although Euron's fleet is sailing for Dragonstone, equipped with Qyburn's heat-seeking surface-air scorpions, all manned by 20 shirtless good men who have the aim of modern-day SEALs.