Either skip the travel or get separate rooms.
DH has been a snorer ever since I met him. I was mostly able to sleep in the same bed as him, as long as I wore my foam earplugs (I've worn them all my adult life, it's the best sleep aid for me), and as long as he was facing away from me when we fell asleep.
Then last year it suddenly got REALLY bad. He had to sleep in a different room AND I had to wear my earplugs, it was so loud. He finally got a sleep study and ranked as severe on their scale (what a surprise). Now he has a CPAP machine and we can be in the same room again for sleeping. We're going on a 10 day holiday together in a couple of months which would have been impossible before he got the CPAP machine. I would have had no sleep, even with ear plugs (and I'm having trouble believing anything would block out the noise).
Your mother's snoring could easily deteriorate before the next trip, and your make-do cover-ups may not be effective.