How to ride more?

Boiling it down to the three primary levers

  1. Ride for longer
  2. Ride harder
  3. Ride more often

But your case needs more nuance, most of which has been touched on already I think.

The two that come to my mind:

Are there particular routes that you could plan and ride that are better (with this objective in mind) than others?

Can you do some indoor workouts that deliver more load / hour in the time you available? For example, I use the TrainerDay HR+ feature to ride at my “Maffetone HR”. It delivers around 50 TSS / hour and is very sustainable for extended periods of time.

Have a listen to this. There’s a lot in it but there is some good advice about rest and when to not follow a plan.