I just spent one week in Palm Springs, CA. in a Time-Share. We ate out three times, one buffet, twice at the Cheesecake Factory. There was much to be tempted by, but I chose to stick with my low carb plan. I slid a couple of times, but not by much. For in the Time-Share I brought my #1 Carb and Zero carb bread with me, Smart Balance with olive oil (60 calories a TBS), Polaner sugar free preserves, Egg Beaters, Sugar Free chocolates (Dove dark, some Russel Stovers), Sugar Free Almond milk (or Silk, low in calories (35 to 40 a cup). no carbs, and had Costco's Chicken Salad a lot (no carbs), lettuce, cucumbers, cherry tomatos, Splenda and such. I also ate fresh strawberries.
Since you are staying with family, could you bring some of your own food choices? Say to them that you have to eat this way because of your health. They will usually not push in that case.
“The biggest seller is cookbooks and the second is diet books – how not to eat what you’ve just learned how to cook.” -Andy Rooney