I agree with the points above. You invested too much in getting rid of estates. Choose between Oasis and Trade Route.
Oasis looks like the stronger option because you also play with Cartographer, and being able to draw one of the cards is really strong there.
With such strong selection (Cartographer) and trashing, you're likely to see your terminals every turn. Two terminals is already quite something, three is too much.
I tried this board solitaire on two different openings:
Spice Merchant / Courtyard and
Trade Route / PotionBoth got me to half the Colonies in 15 turns. I think I'm really lucky in the first one, and I "compensate" for that later on by buying a clumsy Trade Route.
The potion actually feels like the best plan on this board to me.
Definitely no straight BigMoney, and going for provinces should always lose to Colonies.