first ironman in 6 weeks what are some key training session ideas

so my first ironman is in melbourne australia in 6 weeks . i got a late entry in thru a charity auction and have been stepping up my training in last few weeks . im just looking at finishing ( on training times maybe around 13-14hrs ) my training is a bit all over the place as i work shift work and have been working a lot of overtime due to short staffing

what do you think are some good training sessions to try and do in the next 4 weeks to help build fitness and confidence. i have a free day next tues and hoping to do a 180km ride on a bike path that runs next to a motorway which is similar in gains and open to the wind as the bike leg