I had exactly the same issue, though I was on the Sheffield side.
We compromised and moved to Glossop. We both had hour and a half commutes by car. We both got home late and tired. Glossop's a dump. We split after 6 months.
Do yourselves a favour and choose either Sheffield or Manchester. From the way you've described it, providing you work in central Manchester, go for Sheffield and train it over. It takes 50 minutes on the train. Plus the riding is better from Sheff