Personally I’d say that the Polarised Plans could be hard work on a trainer if you aren’t used to indoor work. Two hours of endurance would be, well to be endured 
The suggested Sweet Spot Base, (SSB) Low Volume would be a better intro IMO. Also as suggested, if the weather is good you can push the weekend ride to “outdoors” The plans changed earlier this year to be a lower stress base for use with Adaptive Training.