BB - like the.idea of an event 31 weeks out - would give me some point of focus.
join your local cycling club and get out on their club rides.... will drag your speed and endurance forward at an amazing rate, plus you'll make a few local cycling friends and will discover a load of new routes, cafes and climbs that would take you years to find otherwise.
Alongside some gentle basework, pick a weakness or two, and work on them.... I've always struggled with hills so have been riding inclines hard, and have stopped trying to swim 'long' and have worked on technique instead.
A slightly different perspective here, but with a similar conclusion.... IF you are motivated, and prepared to train hard, the IM is acheivable in the timeframe you have laid out... I went from heavy smoker to IM in 12 months.... however, there is a big but (double entendre entirely intentional!).... I also have two kids, but they are both grown up.... don't understimate the points made by several people above about the commitment you'll need to make to training and the impact on your family... my kids, being grown up, didn't care that their dad was out running at 5:00am, swimming in the evening, or locked away in the garage on a turbo trainer.... and gone all weekend on his bike, and my better half enjoyed the peace and quiet!.... wth two very small kids, you'll be putting a massive amount of work and responsibility on your partner, just when they need your help the most with a new born, and second to boot.
So, I think you 'could' do it...... but whether you 'should' is a different matter.... but then again, probably wiser to listen to Flyaway's advice, as she is usually just finishing the marathon as I finish the bike leg....