First of all, have you talked to your boyfriend about this and is he willing to move at some point? If not, then that is something you have to consider in your relationship before you think about anything else.
While I didn't grow up in a small town, I was pretty much raised in the same house until the day I moved in with my husband, then boyfriend at the time. I never thought I'd leave the state I grew up in. My mom raised me as a single mom and I have no siblings so my mom and I are VERY close. My husband, on the other hand, couldn't wait to leave our state. He wanted a new adventure and it never felt like "home" to him. I had to decide if I would be willing to move with him at some point and he had to decide if I didn't, if he would be willing to stay where we were. Do you see what I'm saying? I don't know if he will or not, but if your boyfriend won't even discuss this with you, that would raise flags with me because I would wonder if that is how he would be when it came to marriage issues, house issues, child issues, etc. and trust me, there will be plenty of them! Marriage has to be a team effort and we have to make compromises sometimes. I just wanted to put that out there because that is just as important as your question about family.
I can tell you, I finally agreed to move out of state (400 miles away) 6 1/2 years ago. It took us a while to make friends and while we have some great ones now, the friendships don't compare to the ones we left behind. It is very much just my husband and me with our children. If anything, we have learned to depend on each other for everything so our relationship has grown stronger but I cannot tell you how sad I was every first day of school when other grandparents would come to see the kids off and my mom was nowhere around or grandparents/VIP(erson) day at school or the day my middle son had his kindergarten moving up ceremony. That day really killed me because my husband's job sent him away on a business trip that they just decided on 2 weeks before. They didn't care about our son's big day and my husband couldn't risk losing his job. It was too late to buy plane tickets for my mom as they would have been expensive. The only people there for the ceremony were my youngest son and me. Soccer games, swimming lessons, field trips...because it means I don't have family to watch my youngest so I can go on field trips. My middle son actually got upset about this a couple of months ago and now my oldest is going on a field trip next week that once again, neither my husband nor I can go on. These are just some of the concerns...my grandmother died a year after I moved so she only got to see my second son a handful of times compared to her memories with my oldest. Every time my mom ends up in the hospital because she has a bad heart, it is very difficult because especially having children in school and no support to count on, I can't just drop everything and go to the hospital. My mom missed my third son's birth because she had just gotten out of the hospital and wasn't permitted to travel yet. She didn't meet him until he was about 2 months old which I know broke her heart but you aren't supposed to travel with a child less than 4 weeks old and by then, school had started.
My husband and I are actually very stressed right now trying to decide what to do for our future. Right now we live in a very safe, beautiful area and the kids go to an absolutely wonderful school. (Safety is something I am guessing you have being in such a small town and you will find that is important when you have children.) On the other hand, we miss our friends back home who were always there whether it was for a birthday party, my mom in the hospital, or anything. We know it will be harder to get the area and schools we have here so we are horribly torn. Oh...when I talk about friends...here is an example of our relationships...back home, if I tell people we are coming for a visit on this day, they are there just like they always were. Here, I have to talk to the families who are most important when it comes to birthday parties and make sure the date works for them first. Back home, my best friend of 30 years has stepped in when my mom has been in the hospital because she knows I can't always be there. A friend of my HUSBAND'S has become my mom's "adopted son" in a way taking care of any maintenance she needs help with. We have very blessed friendships back home but we find ourselves debating is it more important to have that support for our family or to live in a safe area with good schools for our children. Back home my mom could stay in her house because it's paid for. To move her up with us would mean us having to buy a multi family house because it's too expensive but my mom is willing to move. I am just not sure we would even be able to afford a house like that up here. I don't know if that's an option for your parents.
I wish you the best and I think it's great you are trying to figure this out BEFORE you end up in the situation. I probably made things worse for you but you sound like me with your parents so I'm being honest with you about what we have gone through. If you ever want to talk, feel free to send me a message.
Good luck A..
L.