Age is just an abstraction, not a straitjacket, declares the stubborn old protagonist in the Canadian romantic-drama “Still Mine,” which opens Friday.

It may be true enough for the film’s lead, Craig Morrison, movingly played, with just the right mix of bite and tenderness, by veteran Hollywood character actor James Cromwell. At 87 years old, Craig remains virile enough to fell dozens of spruce trees growing on his 2,000 acres of land in rural New Brunswick. He even mills the lumber himself. Then, practically alone and by hand, he sets about building a neat little one-story frame house for himself and his wife of 61 years, Irene.

Portrayed by the captivating Geneviève Bujold, Irene is in the early stages of dementia and can no longer comfortably navigate the sprawling, but crumbling old farmhouse where the couple raised seven children.

In addition to his wife’s increasingly fragile condition, Craig is beset by problems with the government. The local inspector insists that Craig cough up $400 for a building permit, submit blueprints for his construction and use only wood that has been stamped by a certified inspector for his frame.

They are just arbitrary and petty bureaucratic demands to Craig, whose ship-building father years ago taught him to look at a tree and visualize the versatilities of the finished lumber. He can also plumb a room to perfection and expertly right-angle all of its corners, so he doesn’t need any stinking plans or permits. As a result, the ornery ol’ cuss ignores stop-work orders, which lands him in a court battle with the bureaucrats.

In the meantime, Craig squabbles with his neighbor and good friend, Chester, over Craig’s headstrong nature, and he battles with an adult son and daughter over the care of Irene. They learned long ago to just yield to him.

For all of his bluster, Craig is not mean man. He is, in fact, exceedingly generous, having deeded over 25 acres of his land to a grandson so the young man could build a house for his family. Craig is reminded by Chester’s wife, Margaret, how 40 years earlier he helped the struggling young farmers stay afloat during a particularly harsh winter by giving them a truckload of fuel and side of beef. Still, Craig is either too proud or too stubborn to accept the offer of a weekly casserole from Margaret after Irene falls and breaks her hip.

At the heart of the film, though, is the tender love story between Craig and Irene as they negotiate their twilight years. After years and many travails together, the Morrisons maintain an emotional and sexual passion for each other. Even through her mental and physical decline, she is as tough as he, vowing never to move into town or a retirement home, where the only movement is the slow shuffle into the ground.

That sort of underscores the urgency Craig feels about finishing the new love nest he started building for them.

“Still Mine” is based on a true story. It is a quiet movie, filmed in lushly bucolic settings. The pace of the film is slow, but never plodding. It is packed with a great deal of emotional punch, largely due to the textured performances of Bujold and, especially, Cromwell, perhaps, best known for his Academy Award-nominated performance as Farmer Arthur Hoggett in the 1995 hit movie, “Babe.” He is an actor of great emotional range, which is stunningly showcased in this small film.