Or send your regrets and a card to their home. No one says you have to go to either event. If it's going to be a hardship to you to attend then don't. If the bride's mother has an issue with that simply tell her you're unable to attend. Don't argue, don't offer excuses.

Destination weddings are for the bride and groom - guests are secondary. The reception is for their local friends and family as well as those who are willing and able to travel.

If I had to choose I'd say go to the reception. The turnout will be better and you'll see more of your family.