I'm 18 and in college, so I'm old enough to make decisions for myself, but I don't know how to tell my parents I don't want to go with them on vacation this winter. I'd rather have the house to myself 
Here's the stitch: My parents want to go up to Minnesota for the winter to visit my grandfather (in poor health) and see a few cousins. We would be there for 2 weeks. The problem is, I don't want to go, at all. My 2 cousins my age are likely (about 95%) to be busy with any/all of the following: any of their 6 AP classes (lots of homework, even over holidays), cross country, basketball for school, club basketball, school plays, work, et. al. I would be up there for 2, maybe 2.5 weeks, with no cell phone service (VERY small town), no internet and nobody to talk to, nothing to do. I was just up there in the summer, so even if I did have relatives I could talk to, nothing new has happened. This is my primary reason for not wanting to go, but, knowing my parents, they will give me the guilt trip and say "you don't want to spend Christmas with your family?" or "We should see grandpa, before he dies." I don't know how to tell them without: A, feeling like a bad person or B, having them get mad. My mom has told me in the past that I can make decisions for myself, and they won't care what I do, but they EXPECT me to go, and I don't know which excuse (below, and all true) would be the most effective in letting me stay behind.
Possible excuses:
I have work for 2 of the days we would be gone, but it wouldn't be THAT hard to find a substitute.
I will be home to take care of our dog, and we wouldn't have to find someone to watch over her.
Its just not fun anymore, I will have NOTHING to do.
I was just there in the summer, I have nothing new to talk about with my 50+ yr old aunts/uncles.
I told everyone in the summer, I probably wouldn't be coming back, nobody else expects me to go.
Its going to freezing cold, further emphasizing nothing to do.
Everyone my age will be busy, I'd spend all my time trying to find the neighbors wireless internet so I could talk to people from here.
Finally, I'd like to have the house to myself for these 2 weeks-least likely to work, don't want to bother even trying this excuse.
tl;dr Which excuse for telling my parents I DONT want to go to Minnesota with them would be most effective? or What else can I say (that I haven't mentioned) that might allow me to stay home?
ok, some feedback, thats good I guess, maybe some suggestions of what to say when they remind me I will probably never see my grandfather again? or that Christmas is a time to spend with family?

Here's the stitch: My parents want to go up to Minnesota for the winter to visit my grandfather (in poor health) and see a few cousins. We would be there for 2 weeks. The problem is, I don't want to go, at all. My 2 cousins my age are likely (about 95%) to be busy with any/all of the following: any of their 6 AP classes (lots of homework, even over holidays), cross country, basketball for school, club basketball, school plays, work, et. al. I would be up there for 2, maybe 2.5 weeks, with no cell phone service (VERY small town), no internet and nobody to talk to, nothing to do. I was just up there in the summer, so even if I did have relatives I could talk to, nothing new has happened. This is my primary reason for not wanting to go, but, knowing my parents, they will give me the guilt trip and say "you don't want to spend Christmas with your family?" or "We should see grandpa, before he dies." I don't know how to tell them without: A, feeling like a bad person or B, having them get mad. My mom has told me in the past that I can make decisions for myself, and they won't care what I do, but they EXPECT me to go, and I don't know which excuse (below, and all true) would be the most effective in letting me stay behind.
Possible excuses:
I have work for 2 of the days we would be gone, but it wouldn't be THAT hard to find a substitute.
I will be home to take care of our dog, and we wouldn't have to find someone to watch over her.
Its just not fun anymore, I will have NOTHING to do.
I was just there in the summer, I have nothing new to talk about with my 50+ yr old aunts/uncles.
I told everyone in the summer, I probably wouldn't be coming back, nobody else expects me to go.
Its going to freezing cold, further emphasizing nothing to do.
Everyone my age will be busy, I'd spend all my time trying to find the neighbors wireless internet so I could talk to people from here.
Finally, I'd like to have the house to myself for these 2 weeks-least likely to work, don't want to bother even trying this excuse.
tl;dr Which excuse for telling my parents I DONT want to go to Minnesota with them would be most effective? or What else can I say (that I haven't mentioned) that might allow me to stay home?
ok, some feedback, thats good I guess, maybe some suggestions of what to say when they remind me I will probably never see my grandfather again? or that Christmas is a time to spend with family?