WiFi to Garage

Dear Netgear Community- please forgive me if a proper solution has been posted elsewhere, and I just haven't found it. All of my researching has led me on a tail-chase, with many options that seem overwhelming. I am looking for a simple solution to extend my WiFi signal to a garage outbuilding about 35 feet away. I have a C3700 moden router attached to the cable feed in an upstairs main room. A bedroom (one interior and one exterior) wall separates the signal from the garage, located across the driveway.) I have converted the top of the garage into a small studio space, where I have installed a Netgear EX 3700 Range Extender. So the signal has to penetrate one exterior wall. It almost works! The indicator light that shows signal strength is red, meaning poor signal, but I am able to connect, even though load times are slow. I have even been able to attempt a Zoom conference from the studio location, though there was feezing and dropouts. I am attempting to boost the signal. Again, there seem to be various solutions. 

1) Buy a stronger Range Extender that can amplify a signal more effectively

2) Attach a directional antenna to the C3700 and point it to the garage(?) This seems like it might work, but I've seen nothing about being able to add an antenna.

3) Daisychain another Range Extender in between the Router and current extender?

4) Replace my current system with a more expensive mesh? I would think the same problem- not enough signal strength to connect to the home modem/router would be an issue like the range extenders.

5) Route another Coax cable somehow...not sure how that would work. The cable signal currently feeds past the garage underground, where it connects to the house, then upstairs to the modem/router. Maybe add a splitter and a different modem/router address to the garage?

I never have to use this stuff, and the tech and knowledge base evolves exponentially while we go on about our business. So when I do need to educate myself, it's a daunting task. Thanks in advance for your time and advice-  JR