It's also worth mentioning that the wheel adjusters should only ever be touched once the cable has been slackened fully. Once both sides have been done, use the central cable adjuster to give the correct travel on the handbrake lever.
It's not trivial crawling under the car to fully slacken the cable. I reckon as lnog as the cable is slack on the brake I am adjusting that's slack enough.
Yes, that's fine from the point of view of adjusting that brake when the lever travel is fine, but the Op is suffering a long brake lever travel, and that's most likely to be down to the cable having stretched anyway, so most likely it's going to require crawling under it to adjust the central adjuster.
If the adjustment is made only at the wheels, it's likely to either leave them binding or without sufficient travel left at the shoe levers to be effective.