For what it's worth I regularly do 1-2 hour rides indoors on a trainer. Just like working on speed, power, cadence, etc, if you go longer then a shorter ride seems fine. A 5 hour trainer ride makes 1-2 hour rides seem short. I use the trainer year round. I've even taken the effort to put my training on Strava so people can see that it's possible to be a somewhat competitive Cat 3 on 15-17 hours a month. A trainer is more convenient for me for various reasons during virtually all seasons here in CT.

I race outside, of course, and I ride outside if I'm on a trip where I bring my bike. At home I tend to pick riding indoors versus going out.

We have an 18 month son at home so when he's awake I look after him. Otherwise I can ride the (fluid) trainer in the office, which used to be the dining room (so it's on the main floor of the house), usually at night or during the 9 hours a week he's at day care.