I think you are asking the right question about who will buy the trees. Where are they getting them now? People who want to take a day or part of a day to have a tree-cutting
experience are not the same group who just wants to get one and take it home. You'll also need a big area for people to park and turn around in, a good sized area to offer flocking, if you want, and a place to put on bases. There is something about if you help people tie the tree on and it blows off, they can blame you for it. So some places only the customer can tie the tree on, facing the correct way, of course.
It will take perhaps 6+ years with you really pampering the trees to get them to all the sizes necessary.
You need to check out insurance for sending inexperienced and possibly tipsy people out with saws and small children running around. Times have changed, insurance companies are not as agreeable as they used to be.
The Christmas tree farms around here have other attractions, like a
tractor that pulls a wagon with people riding in it, picnic tables, donkey rides,
straw bale mazes. They also do pumpkins and mazes for Halloween, so they are covering two holidays.
Sell hot chocolate and
coffee (needs a permit.) Know the rules, like there has to be 2 gates for cars to enter and leave, and not run into each other in a muddy parking lot. Mud will be everywhere, slippery ice and snow. People do the craziest things in parking lots, sometimes even stopping right smack in the middle of the driveway, blocking the whole place. Do you have a truck you can pull them out if they get stuck?
Do you want every holiday to be a working holiday? All those weekends you'll have to work, while your family wants to go do something on the weekends. I caught a lot of grief for this one.
One of the older Christmas tree farms here just cuts their trees and sells them on a small,
local lot, already on wooden bases.
I think what it comes down to is, do you want to spend the first 3+ weeks in December, (and possibly the 4 weeks/weekends of October) in the rain and snow and cold wind, outside with people who show up at random times, (who don't show up if it's raining, sometimes they will if it's snowing, and fewer in bad winds.) I've seen rainy weekends in October that just ruin the business of the straw bale mazes. You have to be open and available for them whenever they show up. Are you really a people person? Do you like spending all day with strangers who come and go, and all the personalities involved with that (and there are plenty). Or are you a grower who wants to spend time growing, and let someone else do the selling? Do you really, really like sharpening saws?
I've noticed in rural areas people tend to grow their own vegetables, have
chickens, so they don't necessarily buy much of those weekly things. Although eggs do well.
If you want to invest in a vineyard you don't want to make wine, you can sell your grapes (assuming they are the right kind and in demand and suitable to your soil) to winemakers. Growing grapes involves a lot of chemistry, soil type, taking care of perennials, using winemaking equipment, understanding fermentation and bacteria. There's lots for kids to learn about the scientific/natural world with something like that. Ice wine is really popular where it's really cold and the wine grapes can freeze on the vine. You are more on your own schedule and can have time for your family.