Assuming I have adequate time to plan getting a dispensation is not a problem. If anything, it is too easy I’m asking, in your personal experience, how burdensome attending mass has to be before you request a dispensation. Do you simply make other travel plans that allow you to attend mass even though you could conceivably get a dispensation?
To answer your question, yes we would make other travel plans if there was no Mass available. For my husband and I missing Mass is not an option and we’ve travel and plan accordingly. In your scenario, if there was truly no nearby Mass, we’d schedule the travel plans so we can go to Mass before/ after the trip. For instance, go to Mass Saturday evening, drive/ hike to the camping area, camp all week, leave Saturday night and make it to Mass Sunday morning. Or leave Sunday morning to make it to Mass Sunday night.
When my husband and I book travel, the first thing we look at, before tickets or trips are booked, is where we’ll go to Mass. I highly recommend
www.masstimes.org, but I always call to confirm the Mass times before we book. As others have said, this has lead to some very memorable experiences. We’ve been to Mass domestically and internationally and I wouldn’t trade those experiences for a dispensation.
Masstimes.org also has a smart phone app and Maps and Local on my Android based phone are awesome tools for finding a church for Mass.
I had a business trip to Denmark and scheduled my flights with a five hour layover in Copenhagen so I could catch a bus to Mass. I had the public transportation Google mapped and had spoken to the priest to confirm everything. A mechanical error in Toronto led to a 12 hour delay and I couldn’t make the Mass. I was, literally, over the Atlantic Ocean for every single Mass time (and missed all the connections in Copenhagen) that’s the only time I’ve ever missed Mass while traveling. (Missed one other time with pneumonia.)
As for the is it a grave sin/ is it a mortal sin question - a sin is a mortal sin if it is grave/ serious matter (missing Mass is) if you have full knowledge that it is grave matter (you do now) and if you freely choose to commit the sin (that’s the part that’s between you and God.)