How to tan leather when playing in cold climates that have no oaks?

[StarFeather]

What it says on the tin. Doing the colder climate playthrough and I realized I can't make tanin without oak logs. Is there a way to obtain them or oak seeds from cracked vessels or trading, or is my only option to go on foot to reach a warm area and import some?

[LadyWYT]

Agriculture traders sometimes sell oak seeds, but to my knowledge the arctic regions don't contain as many traders. Traveling to a warmer area to get oak wood/oak seeds is probably your best bet.