How to battle blowing it at holiday meals and bbq's

I try to do little things, like no bun with my meat (weather it be a hot dog, burger, sausage etc). Only one serving, do not go up for seconds. Try to stay away from the creamy salads. Try drinking lots of water before you go to fill you up.
But having said that you do need to let yourself enjoy from time to time or you really will go off the rails.
Good luck.

I just indulge for holidays and when out of town family get-togethers happen.... and then fast the next day. Calorie deficit and McD's both achieved.

I had the same problem last summer since we host a bbq most weekends, and those that we don't it's usually because we are attending one at a friend's house. So, now I just eat less calories during week so that I can indulge more on the weekends. That, plus getting in a good morning workout on the weekends, has worked for me.

Perhaps eat whatever is healthy eating to you before you head over to a gathering. This way, you've had something already good for you and perhaps won't binge on too much of anything else being served. You can still socialize and have a beverage in your hand, and maybe just only eat dessert, or have a nice helping of fruit if served.

portion control and exercise

i second this. also, maybe eat a little less earlier in the day.

sometimes these events have a salad. sometimes they don't. bring one. load up on it. lately, i've also been loving grilled vegetables, like peppers, asparagus, etc. corn on the cob is good too.

and grilled plain old meat is pretty healthy. it's the bbq sauces that have a lot of "bad stuff" that people don't like. so just call ahead and ask for a few pieces of meat that are unmarinated.

burgers?? ask for lettuce, tomato, and onion on that piece.

but you know what i think kills a lot of people at these bbqs?? the booze.

Fresh fruit especially melons and grapes ate huge successes at bbqs in the summer. Snack on some of those with water before you dive into the "meat and taters". It will help with portion control. Let's face it. It's so much easier to grab a half slab of ribs smothered in sauce than it is to slice four ribs off of the end when you're on an empty stomach. Also, as mentioned above, trade off the potatoe salads for corn on the cob.
Also invite new dishes to the grill. Chicken, pineapple, and cherries on a kabob with a raspberry vinegrette drizzle cooked on the grill beats a hot dog any day.
Remember to occasionally reward yourself for good practices to prevent a burn out.
Good luck with the next bbq.