Yet women are later apt to discover they have failed to prepare sufficiently for retirement's demands.
A 2010 Employee Benefit Research study found that single baby boomer men, compared to their married counterparts, had a 19 to 34 percent higher 'savings deficit' for their retirement.
But the same study found the deficit for unmarried women to be at least double that of married women.
Di Vito said that once a senior suffers a drop in income, statistics show it's very difficult for them to climb back.
BMO's report advises current or potential singles to do six things in order to meet what it calls the "distinct challenges" of being retired and alone:
Plan for retirement as early as possible.
Build and sustain wealth.
Understand income and expenses.
Consider changes in housing needs.
Focus on social and emotional well-being.
Devise a comprehensive health strategy.
According to a 2010 U.S. Consumer Expenditure Survey, housing expenses account for 37 percent of a single person's income, versus 32 percent of a married couple's.
For that reason, single retirees need to keep a close eye on housing costs and, when necessary, lower them, said Di Vito.
The BMO report suggests that the single retiree consider living communally or taking on a roommate—what it calls the "Golden Girls" solution.
Not only does this help reduce costs, but living with others helps guard against depression.
According to census data, 557,000 seniors aged 65 or older already share some type of shared housing arrangement.
North Carolina retiree Karen Gulledge's husband, a state civil engineer, retired in 1990 and died in 1996. "He had heart trouble," said Gulledge, 70, "but even so, you never are expecting it."
One of her first tasks was to sell the family home and move into a townhouse with lower maintenance costs.
"I hated to do it," she said. "We'd been in that house 28 years. But it was the only answer."
On the advice of her and her late husband's financial planner, Jim Trull of Keystone Financial Partners, she put "a lot of money" into an annuity. That has helped her to maintain her standard of living.
Asked what her advice she'd give to somebody facing retirement alone, Gulledge said: "Plan everything you possibly can. Meet with a financial planner early. Make sure you know where all the financial documents are kept, and make sure they're kept in order."
Beyond taking the necessary financial precautions, Gulledge advises to take social ones as well. "Friends become very important. They help you through it, she said. "You have to develop a new core of friends."
Dorlene Zaslow said it's important to keep busy. She does Pilates, keeps herself "super fit," and every now and then travels to New York to see a show. She's dating a man 16 years younger than herself.
"I try to be happy," she said. "You have family and friends. But basically, you're on your own. At the end of the night you're by yourself."