For a task like this (for any Wine porting) I would highly recommend Wineskin. Just Google for it and also for this: "WineHQ AppDB" which is a database that often offers helpful information about results in testing and also getting various games to work with Wine. This info can be invaluable when using Wineskin to port a game successfully.
I took a few minutes to check into Heroes VI but the results were old and the Wine versions tested were significantly out of date. So unfortunately, in this particular case it was hard to find much useful information beyond that it seemed to "mostly" work but with some issues. Those things may or may not be a problem anymore as Wine is constantly updated.
You might want to use Wineskin with the lastest engine (version of Wine) which is explained in the docs for Wineskin. Honestly it is not all that complicated. I had the basics of using it under control in an afternoon of tinkering with it and went on to port a number of games successfully, along with AppDB's help for info about each one.
All that said, I'd caution having lowered expectations for this particular game even as I hope that you make out well. If you already own it, try it and see and hopefully it will wind up being worth the time spent. If nothing else, you'll learn a lot that can be quite handy in the future with other games. Some stuff runs beautifully with Wineskin's help.