Mid Volume vs Low Volume with extra workouts

Have been doing Low Volume AT since the spring, sticking with my plan and TSS until my last A race in mid September as it will be tapering me the next couple weeks but I am interested in starting to add in some extra structured volume through the fall Cyclocross season and winter-spring.
How do you decide between continuing low volume with an extra 1-2 hours of riding per week (through train now or an extra workout) vs moving up to mid volume?
I’ve made some good progress this year and have increased my FTP by 38 watts since the spring (3.772/kg now) but would like to get >4w/kg before next season’s races start in May (another 27 watts would put me ~4.2w/kg).
I’m wondering if I should move to midvolume after my race or start doing extra train now workouts or add in a couple 45 min TR sessions per week doing something like Carter +1 Log In to TrainerRoad or West Vidette Log In to TrainerRoad . How much intensity do you need for a 45 min workout to be effective? Do I need something with higher intensity (IF) like Ainslie -4 Log In to TrainerRoad to make gains with a couple extra 45 min workouts per week?

Separate question but the CX calendar hasn’t been released yet so as of now my plan ends a week after my last road race in mid september, will add the CX races I can do but after that if I put in a hypothetical May road or xco race in my calendar will AT give me a solid few months of Z2 base training over the winter? I’ve never done a winter of structured training so am hoping for some good development from a few months of base training.

Many here would argue that Low Volume is plenty enough intensity for everyone regardless of whether you do 5 hours a week or 20. It’s the extra rides you add that will either be longer or more frequent. I think 2 intense workouts a week is enough for me, but I typically do 10-11 hours total either by extending workouts by 30 minutes or planning long z2 rides in between.