I lived in the North of England and was impressed with the number of travelling trucks enterprising business people had to service people in rural areas. There was a general store - type one, and a sewing one, and a butcher. I often went to the cafe truck which used to turn up at sport events or bus stops to sell coffee and cake, fast food etc. It was warm to sit in rather than tand outside. Anyway, as long as you do your math etc., I think it could be very successful. You may find it helpful to look up when the local markets are on in each place and park your truck nearby so that you have a ready crowd, or supply other necessary items (perhaps tools) other than sewing, to encourage customers.
In the area I live now, a man comes up from the coast and sets himself up in the local church hall. He puts an advertisement in our local paper about a week beforehand and emails all of the quilt groups or previous customers that he will be coming. Good luck with the enterprise and 'go for it'.