Train now takes a lot of guess work out of it and is the easy button.
Taking life time commitments into consideration, if you can commit to additional 60 minute z2 rides I’d opt for more frequency and increased volume before making your existing less frequent trainings longer. Z2 is a safe addition to any plan, especially since durations are <2hrs. Just don’t sacrifice sleep. Or you can blend the two and add 30 mins to a sweet spot workout and add a 4th 60-75 min z2 ride in there. Could be a good hybrid.
Bottom line: whatever you can stick to to safely increase volume and recover properly. Then the camp you’ll be recovered and raring to go!