70.3 to full in 6 months

Did Mont Tremblant 70.3 in 6h45 in June. Was not really satisfied with my time but had some smallish problems with my bike which lost me maybe 20-30 minutes. Swim was pretty easy. Bike was very hard, but I think the Tremblant course is especially hard with a 10km climb to end the bike. Run was not very hard, but I ended up going slow asf to survive from being cooked on the bike. My half marathon PB is 1:30 but I did this one in 2:15 (yikes). Main goal was to finish but I was hoping for sub 6h30 or even sub 6.

Targeting IM Texas in July. Bike is apparently flat which was my main problem at Tremblant. Running my first marathon in September (currently doing 40-50ish a week). Not doing much biking or swimming recently. Say I give myself one or two weeks after my marathon, that'll leave me with 6 months of building from the current "baseline" I have.

Thoughts?