Sorry to hear Ethan. Sound like you will be limited to indoor activity. Can do some yoga, foundation or rev work.
Once you get back I would look at starting with either our sweet spot 1 or sweet spot 2 plan. Really depends on how you feel after 3 weeks off. After about two weeks into training I’m sure you would be ready to jump right back into sweet spot 2 work. After either one you could roll into sweet spot 3 and then a race specific interval plan.
Ethan! No bike riding?? Oh man, for 3 weeks. What are your resources, where do you live?
Hang in there. Like Coach Jake advised - do more REVO and search the froum for home strength and conditioning routines. I posted the home routine last week
I teach art in Bangalore, India and there is a tight lock down. No cycling or other actives. It is bummer, yet we are healthy and safe. I will start some at home workouts and then hope for a short quarantine.
The lesson learned is to order the trainer a week earlier…