Jon, my advice to make the best use of 3-4 days.
1. While possibly difficult if you leave the UK on Saturday morning, an arrival in Halifax prior to 2:00 pm enables 18 holes Saturday before sunset in late June / early July. Choose the Links as the round will be quicker and the course closer to both the airport / resort. Have dinner either at the restaurant or the pub on site.
2. That enables two rounds on both courses plus a trip to Highland Links. So I would recommend 36 at the Cliffs on Sunday. On Monday, head to Highland Links via the quickest route. After the round follow the Cabot Trail counter clockwise. It is one of the great 3 hour drives in the world. Then play 18 at the Links first thing Tuesday morning before heading to the airport.
3 Other non-golf stuff beyond the Cabot Trail.
- breakfast at the Downstreet Coffee Company (owned by Cabot Links) in town
- Sunday dinner at The Glenora Distillery 10 minutes from the resort. The locals call it just The Distillery. Other option is a lobster supper around Chetiacamp.
- Monday dinner at the on site restaurant you did not eat at on Saturday
- Tuesday lunch at The Red Shoes Pub in Mabou on the return to the Halifax Airport. By the way, the possible 3rd course site is near there. Other option is Saturday lunch on the way in, if time to still get your game in.
- on the Cabot Trail the best drink or snack stop is The Rusty Anchor
Suppose if your time is tight a tough choice of excluding Highland Links or only one round on each course.