I agree with starting with your affordable option and commuting.
Starting at the dream school and transferring could cause you to lose credits in the process and increase your cost.
I think emotionally it will be harder as well. Start where you know you will finish. Get invested in clubs and activities, research, make connections with students and professors.
Your mom did you a disservice by not having this conversation sooner but it is what it is.
Keep your undergraduate debt as low as possible.