It would be interesting to see somebody successfully subvert a lot of the common time-period norms. There isn't any rule written that all pre-industrial societies [i]have[/i] to be patriarchal. You'd have to attend to the reasons why gender stratification existed in the first place (primarily, the difficulty of maintaining households in time periods where there was no microwaves or washing machines or Lysol, or the reality that having and raising children was vital to the community back then because infant mortality rates were so high and there were not a lot of nursing homes around). I have definitely seen it done successfully. The Adem in the Kingkiller Chronicles come to mind, where the society is so matriarchal that they believe the idea men have a hand in conception is foolish, and don't see a connection between sex and reproduction. You can do a lot of things, especially when writing about societies that don't exist, whether they are in fantasy worlds, or set in the future, or set in an alternate version of our world. Make a Gay Caliphate on Mars. Your options are limitless.

What you should avoid is the thought that your morals would somehow bring about a utopia. Question yourself a lot. If you made a society where your belief, whether it be third-wave feminism, or Christianity, or egalitarianism, became the moral norm, would that really mean the end of society's problems? Would a feminist society, where your beliefs became law, actually manage to eliminate prejudice? Finding the holes in your own ideas and reflecting on what they would mean will make for the most interesting writing. And really, it makes you a better person.