Just like those who can knock out a weekend marathon without flinching appear to be superhuman to the couch potato, a 40 odd mile round commute can be an everyday occurence for a diehard cycle commuter. There are a few on this forum who do those distances daily. Certainly don't expect to go from zero riding to 5 x 44 mile consecutive commutes overnight, but it's perfectly manageable in the long term as you improve your fitness and endurance. The only limitation will be time in the saddle, but if you enjoy it, it's not an issue really is it! As others have said, as you are going a long way and walking your bike home would be an arduous and drawn out affair, make sure your bike is well serviced and you know how to do the usual roadside fixes if you don't want to be ditching the bike and calling a cab. I look forward to hearing of your success! You can do it
If you can train up to a 10-15 mile ride on your own time in the evenings and weekends, I think you'll be perfectly capable of handling this commute.