I'd maybe do some long sessions in endurance heart rate zone, or maybe sweet spot training if you really wanted to follow specific plans.
Given you're going to need to do a SR to get on PBP, I would say you're going to do more than enough riding this year to be pretty fit for the ride itself.
Being tired and hating your bike / missing a turn / wasting time / your own brain will be what gets you.
I'd maybe do some long sessions in endurance heart rate zone, or maybe sweet spot training if you really wanted to follow specific plans.
Given you're going to need to do a SR to get on PBP, I would say you're going to do more than enough riding this year to be pretty fit for the ride itself.
Being tired and hating your bike / missing a turn / wasting time / your own brain will be what gets you.