Well, I'll throw you a curve. I have a dispensation from my confessor that removes my obligation to attend Mass while on vacation. He says that there is a difference of intent in going on vacation to skip Mass vs skipping Mass while on vacation. He also gives me a dispensation for my job, as I am sometimes "on call" for over 24hrs on weekends, and he has allowed me to sleep, rather than attend Mass in a "sleep drunk" stupor.
I have basically learned it this way: Mass attendance is a discipline enforced by the Church. It is a mortal sin to refuse the discipline of the Church, as she is Christ's body on earth, but if I fully submit to the discipline of the Church and participate in the sacrements and follow the advice of a dully anointed Priest with valid Holy Orders, then I am not sinning. Priests of the church are allowed to grant dispensations on a case by case basis, if approved by the Bishop, I believe. My confessor is very good friends with the Bishop, so I do not think that he is a rogue priest.
I even remember a Bishop in Pittsburgh, PA granting the entire Irish community of Pittsburgh a dispensation to eat corned beef and cabbage on St. Patricks day when that day fell on a Friday during Lent
My only point is, if you are worried about sin, talk to your confessor

, not us. He has Holy Orders, we don't
God Bless and peace be with you