What kind of help does/will your relative need/ expect?
How much free time will you actually have?
WIll you have your "own" space while there?
Have you considered hand- piecing projects instead of machine sewing them?
Are you planning/hoping to bring " everything" you need with you? Almost with an assumption that "nothing" will be available/accessible once you get there?

Maybe a folding table to sew on.

I’m sure there will be a little time during the day and certainly time at night and on weekends. There are some stores around. I can always buy what I’m missing. We have room to bring some of my stuff. I would like to bring my machine. There probably won’t be a place to keep my machine setup and I will have to transport it from where we sleep to where we work.

i think I’m going to have to choose projects beforehand and bring the appropriate fabric and rulers with me.

well you’ve given me a lot of information. Thanks, I’ve started a list.

I usually go to a friend's home in AZ to have a private quilting retreat. The week before I leave I have a box/basket I throw items in that I want to have when I am in AZ. Luckily Amazon is a quilter's best friend - items can be ordered and delivered in a few days. I can't imagine planning out a 6 month trip, so knowing there are stores around, I wouldn't worry about missing a couple items. And I agree with the idea of buying a machine when I got there is I could not take mine in a car with me. I don't trust luggage handlers and or delivery people at UPS/USPS/FedEx, etc. Also, If you have it professionally packed that will cost an arm and a leg.

I agree with everyone about the iron which is what I noticed you didn't list. When I go for any length of time on the road, I put each project with fabric, pattern, needle and thread, small scissors in a container. Then it is all ready to pull out and start on a project. I would be very skeptical to ship a sewing machine-especially if it is computerized. Do you have a feather weight? It would be small enough for you to travel with if you are driving.

don't forget the power cord for your machine, ott lamp, ripper, and spray bottle, oil for machine, extra bobbins, do you use readers when sewing?

Iron...I bought a small travel iron, palm size. Just love it. Rarely, and I mean rarely, do I use the other iron. Found mine at Walmart for under 15.00. Small, compact, and really gets hot. Only down size...no auto shut off.

After reading other posts, just a different perspective. Prioritize what you bring. I wouldn't bring anything I knew I could buy locally. Remember, storage area for your sewing machine can hold a lot of sewing notions.