Keep in mind that companies break promises on this, even for people who have already retired. My brother and his wife have had to scramble for insurance through the Exchange for 2018 because the Megacorp he left 2 years ago is no longer paying for retiree health insurance. They don't qualify for subsidies and they've got 3 or 4 more years till Medicare. They'll be paying about $22,000 in premiums. They'll be OK- he has a good pension in addition to their savings and their expenses are modest- but it's a huge shock. One of my previous employers froze payments for retiree health insurance at 2014 levels, which wasn't quite as bad.
Not anything you can predict- just be aware that you could hang on for 44 months and find that "benefit" is less than you expected.