I'm not sure what your state regulations are.
Your property sounds ideal for raising goats.
A friend of mine raises a lot of goats for meat and she never has a shortage of customers. What she does is buy bucklings from a goat dairy. She pays between $7-12 per kid and usually buys 8-12 at...
The main reason for drying them out two months before the due date is so they will produce colestrum for the babies.
Mine get dried off every fall whether they will be bred or not...because I don't like to milk in the winter. :P
It sounds like they had a good time. Keep a collar or short tether on your lead goat and that way when they do get into the garden you can just lead her away from it and the others should follow. They might complain about it, but if you keep walking away they will follow.
"We thought we might try supervised free-roaming."
That is one of the joys of goat keeping. It does depend on your goats and how friendly they are towards you. Actually as long as your alpha female is people friendly and will follow you the rest of your herd will follow her.
Maybe you...