Workout substitutions in 8-week Polarized High Volume Plan

Excitedly found the polarized plans today, which made scheduling my winter season much easier. I am curious about people’s thoughts/advice on ways I was considering modifying them specifically to me.

For background, my main goals relate to long-distance riding. Normal summers involve doing one or two 200k rides per month, a full basic brevet series, at least one 600km+ ride per year as my “A” event, and maybe some long gravel “races” for fun, that involve drinking beer during the event…

I have not had luck with SS-based training in the winter the last two years, especially with SSB on TR. The regular high-intensity rides are too much for me (just takes one night where the kids don’t sleep well, or a week where I’m working nights, and the wheels fall off), while doing lower-volume SS plans lead to eroding fitness because I’m not on the bike as much as I’m used to. The first few years I started biking I got a lot out of SS work, but that seems to no longer be the case. I do find benefit to doing some regular SS work to help increase time to exhaustion close to threshold, as well as climbs and whatnot.

With that in mind, my plan for the winter now is to do the 8-week HV polarized plan, then move to HV SPB.

One thing I was looking at doing was adding in a basic 90% sweet-spot progression somewhere in here. Something like 2x20, 2x25, 1x45, etc. I am not sure the best place to sub this in though. I had considered either making the second day (“wednesday”) each week during the polarized plan the weekly SS day, or alternatively, subbing in my planned SS progression on the “sunday” SS sessions in SPB. Would love to hear people’s thoughts on this.

The other thing I had been looking at doing is replacing one of the weekly shorter z2 rides from the polarized plans with one of the “tempo” rides from TB HV2, like Escondido, Garhuanga, etc. I think doing some low-tempo/high Z2 work like this helps with my sustainable power on long rides. I also find them more interesting than just slugging it out at Z2 forever. Again, the question is where to sub them in during the polarized plan? I had been thinking maybe replacing the “saturday” ride with one of these?