Bonnie Jansen on the 'Football Fever' Podcast she does with Piney said this week that she was talking to one of the Nix staff/mgmt and they were looking at adding a stand or two to Jerry Collins for next season having the Men play there, not sure how much truth is in that, but Piney repeated it later on too.
May well be the better option giving crowd numbers, would mean more travel for the Wellington City based fans but the cost of the stadium openign for 8k fans is silly. What is JC stadium's capacity is 1900, so you'd need to get it up to 10k minimum to cope with the men's games (which is more than a stand or two).