I've driven some very long distances to buy many of the 19 canoes and kayaks I've owned. Once, 10,000 miles—directly from Connecticut to Sacramento, California, about 3,000 miles, plus a very circuitous route back home of about 7,000 miles, paddling all over the western USA and into Canada on the way back. That trip took seven weeks.
What I have always done is to incorporate a paddling trip on the way back into the purchase trip. These would always take me to paddling venues I'd never been before and which I may never have paddled. I traveled twice from NY to Florida, once from NY to Georgia, once from CT to Virginia, and many other purchase trips between 500 and 1,000 miles.
These trips have been among my most memorable paddling trips, or any trips, of my lifetime. Of course, you have to be creative in carving out time to do this, such as planning nearby business trips, getting "sick", or getting old or sick of work and retiring.
Sometimes there's another canoeist nearby the seller who can hold the canoe for you while you gin up the time for the pickup trip.