Power line adaptors aren’t bad, but they are hit or miss. If they hit, they’ll work well and solve all your problems for minimal cost and effort. If they miss you’ll probably never get them working properly. It’s a bit of a gamble, but I wouldn’t rule them out.
Wireless range extenders/access points/mesh networks are the reverse. They’ll almost always work, but they make the inherent problems with WiFi worse. More latency, more congestion, more interference. They’re not without downsides.
Running a cable so you can move your router to a better location would be my number 1 choice. Ideally somewhere where you can plug multiple devices (TV, consoles, pc, etc) into it so they aren’t competing with the devices that really need the WiFi.
Walking pollution: …
That’s right, bike pollution is less than walking (or running) pollution in terms of CO2 per mile travelled. Cycling typically burns ~⅓ of the calories compared to making the same journey on foot and there’s a direct link between calories burnt and CO2 produced.
Cycling at 12mph takes roughly the same energy as walking at 4mph. You emit the same CO2 per minute, but get there in ⅓ of the time. Running at 12mph takes 3 times the effort of cycling at 12mph. You’ll get there in the same amount of time, but breath out 3 times as much CO2. Bicycles are more efficient than our own two legs - how cool is that!