I don't know if anyone else mentioned it, but if you have anyone else you two would like to remember on your special day you could have a memory table with the wine. A pretty sign with pictures of people around with wine wine would be pretty. It could say something like 'Though they can't be here today, we want to toast our loved ones and invite you to take wine home and do the same.' Then you can have the people who want it take it and know not to open it now.
Re: Very unusual favor... is this tacky?