Okay, so here is how I did it (savegames attached, including the 880 one):
This game was off to a great start as Byzantium didn't have Farriers, so I could trade with Bulgaria and Byzantium and got an additional 5 techs, including Machinery and Feudalism. Orthodoxy spread quickly, so all I had to do was tech Vaulted Arches and then go for Plate Armor (followed ultimately by Chivalry).
I made 22.5k food until the game was over in 1290. 25k seem possible, but even for 30k I'd have no idea what to do...
By the year 1017 my Empire looked like this
I settled Kiev on the spot, used 1 Horse archer to raze the road all the way down to the iron, 1 horse archer each to "meet and great" in the north & south (north: follow the road to vikings, germany, french, spain, cordoba and then possibly back home; south: arabs, hungary, venice, poland, back home)
my other 2 town were the one next to the deer/fur in the north and the one above the wheat in the south(-west) - I think thats the ones you meant as well, ezzlar, or? (there is also the wheat/iron-combo along the barb highway)
By the time of this picture my settler for city no5 is finished, a crossbowman and a road leading to the stone awaits it, so by 1023 the city will be built.
so far all I built where workers, some archers/crossbowmen and settlers.
Plate Armor is ready in 6 more turns.
My city no4 is founded closer to Kiev than you seem to do it, I do this as I don't mind the little overlap and I can move defenders more quickly among the cities.
By 1100 AD My empire was at 8 cities:
The one next to the stone mentioned above is in red. Kursk flipped (blue) and I recently founded 2 more cities (green). The one in the south is in Kiev (Province) placed to that it will reach Barley and Wheat (the one close to Kursk), the other one will steal Moscows Horse and get the Pigs in that area.
I built: 3 Granaries, 1 Wall and Pressburg Castle, and 3 Churches+3Monasteries, so far. No other buildings, just expansion.
Currently building 2 armored lancers to take out the 2 independent cities in the North (Minsk&Smolensk)
28 Horse Archers killed so far, 16 Workers currently active. This was a really "barb-free" game. In the previous one I had twice as many.
The year 1203 AD (1 turn before the research of chivalry):
In the north I conquered the 2 independent cities and founded one in the province north of Minsk.
In the south these are my final cities. Armitrevka might not the perfect but the silver would have been pillaged anyway. Also: This is where about 45-50 of the 60 Keshiks attacked. Once or twice there were 7-9 close to the city (5 spawned on the previous turn, too far away, moved closer and 4 more spawned closer as well). If you get more food this becomes infinitely easier, as you'll have your golden age much earlier and thus more knights ready. still, I managed to kill all keshiks on the offensive (although fortified Woodsman3-Macemen on 75%def-tiles helped).
At this moment I am 5 turns away from UHV1, at 12k food (+300-350/turn) and own 10 provinces.
In order to get 30k+ food you'd need a lot more cities, but how do you do that? The independent cities in the north block expansion untill you can built 2 lancers and in the east there are the horse archers...
I'd love to see a similar game description for a 35k+ food game.