Do doctors adjust sleeve size based on patient needs? Can I request my sleeve to be larger than 2 oz.?

I travel a lot. Which means I spend half of my meals eating with others in restaurants. I am investigating the sleeve, because my weight yo-yos during the seasons that I travel. Every summer I lose 30-40 pounds and every winter I gain it back. And I'm worried about adjusting to such a small sleeve and getting the calories and nutrition I need once I've lost most of my weight. I'm actually okay with a less rapid weightloss, and hoping to keep a little bit of my natural curves.