Don't know what your settings were but I was on the "high" preset before. Might try fiddling with the grass detail settings later (I think all the long grass that was shown off in the trailer may be the biggest culprit).

I am technically below spec (rx 570) and had similar performance in the base game. The only setting that helped was lowering the resolution, and when i did i could actually push around half the settings to medium from min. Outside of the map and icons it wasnt actually much of a downgrade surprisingly, so i would reccomend trying that and see if it applies to you.