Here is my 11 turn solution including trashing. Up to turn 9 this follows my solution for the lucky chancellor puzzle . There are opportunities to do more on turns 10 and 11 so perhaps better solutions are possible.
#1 - buy ironworks
#2 - buy chapel
#3 - buy ironworks
#4 - buy cellar
At this point we have have the worst draws, all copper and estates, but are not dependent upon 5/2 or 4/3 splits. On turn 5 there's a different continuation if you immediately draw the cellar and use to cycle cards but only trash 3 with with chapel. The worst draws puzzle is pretty bad to prove since I should really exhaust all possible draws.
#5 - ironworks, chapel, copper, copper, copper: ironworks gains great hall draws copper, chapel trashes 4 copper
#6 - 3 estate, 2 copper - do nothing
#7 - cellar, ironworks, chapel, copper, copper: ironworks gains great hall draws copper, chapel trashes 3 copper
On turn 7 the cellar will find the chapel if it is not originally in hand, so having it hand becomes the worse draw. After turn 8 we have a deck where we can play out all the non-terminal actions and leave the remaining cards as a five card hand. The original 5 cards drawn are not particularly relevant. I'm ignoring the play of the serial cards for brevity.
#8 - Ironworks gains great hall draws estates, chapel trashes 3 estates and cellar; ironworks left on deck.
Deck consists of 2 ironworks, 3 great halls, chapel
#9 - Play out cards to leave ironworks, ironworks, chapel, great hall, great hall in hand
Play ironworks gains village
Play great hall draw village
Play ironworks gains remodel
Play village draw remodel
Remodel chapel to feast
Play great hall draw feast
Play feast gain highway
Buy peddler
Deck consists of 2 ironworks, 3 great halls, village, highway, remodel, peddler
#10 - play out cards (including one ironworks gaining great hall) to leave ironworks, peddler, remodel, highway, village in hand, great hall in discard pile
Play village draw great hall
Remodel peddler to king’s court
Play highway draw king’s court
King’s court on ironworks gaining 3 highways
Deck consists of 2 ironworks, 4 great halls, village, 4 highways, remodel, king’s court
#11 - Play out cards to leave remodel, ironworks, ironworks, king’s court
King’s court on ironworks (king’s court, province, province) drawing king’s court, province
King’s court on ironworks (province, province, province) drawing 3 provinces
Deck consists of 2 ironworks, 4 great halls, villages, 4 highways, remodel, 2 king’s court, 5 provinces
Chapel, ironworks, cellar, great hall, village, remodel, feast, highway, peddler, king’s court