With time like that the best approach from a TR perspective would probably be a SSB Low Volume plan. It will generally be 2x1hr during the week and then a 1.5hr session on the weekend. You could just skip the weekend session and get your outdoor ride in but then if the weather is bad you have an indoor workout ready for you.
I would do it through the plan builder so that adaptive training will work to try to give you the correct ‘level’ of workout. And don’t forget to complete the post workout surveys so the system knows how you’re doing.
And as others mentioned, indoor trainer sessions can be unexpectedly intense and mentally draining so keep an eye on that and remember that no workout is important enough to dig a hole that causes you to skip the next 4. So recognize if you are getting burned out on your current approach and change something up.
EDIT: if you want to try out TR for a month I have a referral code you can use. Just send me a DM on here and I can get you the link.