Run, strength, bike. How on earth would I manage this training mountain?

I’m in the UK so can ride through the winter.

Main goal: 3 day mountain running race at the end of April.
Secondary goal: to be able to go to the spring and summer xc races, with the ability to keep the bike moving along nicely. XC tracks are so much more fun when you are fit enough to be fast.

I’m fit enough generally, for instance I recently rode a 4 day bikepacking trip and happily peddled for 10hrs a day with 2000m + climbing/day. I’ve been riding for so long that I can do it in my sleep. I’ve also ridden mtb and cx for decades, so my skills seem fairly locked into my mind/body.

What I’m missing is the ability to dig deep at race pace. I lack that intensity training, hence why I’m interested in TR. It holds you accountable to the efforts. Plus, and this is a big plus, I want to give AT a proper go. I’m interested to see if it’d help me manage things. Even if a lot of my fatigue is coming from another source, then my survey responses should keep me on track shouldn’t they?

I’m wondering if i dropped the threshold run session on a Wednesday down to z2, then I’d only have one vo2 session on the calendar (Mon, track night). That would free up a space for one hard TR workout.
The rest of the week could be all z2 stuff with the exception of a TR SS workout perhaps? That would still give me time on my feet for the running, with just a tweak of where im getting my cardio from.