Alrighty, here are my 20 turns:
Pre-flight: Set governor to "Emphasize production". For those who never did that: upon growth the new born citizen immediately gets to work and you actually get those shields. This does not work for commerce or food, so always emphasize production (default for new cities too) at the start of a game. In this case the worker in Bergen will finish 1 turn earlier
2110 BC Settle Copenhagen, protect with warrior, set to product worker. North-east curragh reveals possible crossing.
2070 BC Bergen worker -> archer. Northeast curragh crosses ocean.
2030 zzz
1990 The latest worker starts irrigating the Trondheim cow
1950 zzz
1910 Northeast warrior finds a mongol city. The archer in the proximity of the Northwest warrior starts to return home
1870 northwest warrior spots brown borders
1830 The curragh that crossed the ocean finds that it's just a small island.
1790 northwest warrior touches the brown borders but does not see a city or unit. Fortunately, shift-d shows Carthage. No trades because mysticism will come in next turn and I do not want to give out writing. Trondheim archer -> Settler
1750 Wheel + Pott + 20 gold from Mongols (for Myst). Masonry + BW + 6 gold from Carthage (for Myst + Wheel). Research max (-3 gpt) to poly
Trondheim to finish a settler, Bergen to granary.
1725 A barb appears, the returning archer will intercept
1700 Barb killed, off to find the camp
1675 zzz
1650 Trondheim settler -> granary. Mongols and Carthage have IW and HBR and are willing to trade for writing, but I hold off as I do not want to put the monarchy slingshot in danger.
1625 Archer attacks camp and cashes 25 gold for our research deficit.
1600 Found Reyjavik. I did not see Bede's dotmap, but it's New City 13. A worker has been working to water that food bonus in the long run.
1575 Northeast curragh spots orange borders
1550 Meet ottomans. We are up Alph + Pott. Trade Alph + 10 g for a slave
1525 zzz
1500 Mongols started writing, because they will no longer trade it for IW + HBR. Carthage will however (perhaps they are doing math?). Poly due in 12 turns. India still doesn't know writing.
Summary: Presumably, we met all the neighbours on our continent. Three core cities have a food bonus, I propose to give them all a granary and build settlers + workers with them. Other cities can provide the military. In addition to our incense there are ivory and dyes, but they are quite far away. I think we should trade IW + HBR for writing to Carthage while we still can, within a couple of turns.
Note: the slave is chopping near Reykjavik, make sure the shields are put to good use (I say granary).