So the question remains: Which tactic gives more range?

There are a few charts that could help you extend your range. LRC & MRC.

If you are en route and ATC tells you that you will have a one hour hold at your destination you could help yourself by absorbing some of the delay en route. Using Long Range Cruise (LRC) will give you a lower fuel burn and a slower speed. Max Range Cruise (MRC) will give you similar results while MRC will extend your range just a bit more than LRC. The difference could be Mach .86 to Mach .77 for LRC and maybe Mach .73 for MRC. A lot will depend on your weight and altitude. This is something we would try to do whenever we were informed of delays down the road.

Lou