Extra miles thoughts?

I’m starting my CX plan next week and wondering what thoughts are on tacking on extra easy miles in a separate ride later in the day. I work at a shop and my commute by bike, riding easy is about an hour and a half one way (1hr by car with traffic). Its almost all on a very flat bike path and I’d like to spend a good part of the summer leaving the car at home and riding to/from work three times a week.

My thought was to do the interval workouts in the morning on the way in and then stay in zone 1-2 on the way home. I’m 25ish pounds overweight so in addition to not having to deal with the car as much, hoping this will also allow me to shed some weight before my season starts on September 11.

I’m just concerned that almost doubling my on the bike time for 3/5 training days for a good chunk of the summer might detract from peak performance come fall. Any thoughts are appreciated! Thanks.