Much like people talk of "wheatwine", I'd say that 40-50% rye in the grist would probably qualify as a "ryewine" even if the other 50-60% was barley. If you sort the "Rye Beer" category for ABV, you'll find things in the Ryewine category.
Based on the tasting notes, I'll bet you can get some good ideas of what to shoot for and what works well. At the very least, you can get a few commercial examples to hopefully try on your own... (Boulevard distributes to MN, right?)
I am a Rye guy...going to meetings....trying to quit....isn't working. I use 70% in my Rogen. If you use large amounts of rye you have to add rice hulls to keep from stuck sparge, a half pound for 40 to 50% will work fine, then batch sparge. Rye has a nice spicy flavor but is very delicate so adding to a barleywine and getting a nice rye flavor will be a challange. If you have used rye before and know the flavor you will have a much better idea of the flavor you are after and if the result is in line with what you can expect from the rye. If you have not used it before I would suggest you try a rogen or at least a ryePA first to learn the flavor profile. 2 row, rye malt and a little carapils and noble hops for bittering with no or very little finishing hops would give you a good picture. If you go to the ryePA go light on the hops and use hops that you know the flavor of well so that you can pick out that flavor. Sounds like a fun idea and would like to see you post after you give it a try!