Yeah we try to keep indoor training rides shorter especially this early in season and winter. Most likely are looking at having to do multiple training rides over the next 4 - 5 months! It is easy to get burnt out on the trainer so these longer rides indoors become more important come February / March then they are November and December.
Typically no more than 90 minutes in November and December. Come February and March 2 - 3 hours.
Now endurance rides also aren’t TSS rides so you shouldn’t just go out there and hammer 90 minutes at threshold and more to get higher TSS, al la Zwift race as well, but you can to some tempo to help.
Most should be in the resistance training phase right now so building CTL is critical! Focus on strength and don’t worry about the TSS too much. CTL will come up once you can get those longer outdoor rides come March and April. Also with weekly sweet spot training which comes in the base phase after the resistance training.