I feel it would be kinda tough: Wedge makes extensive use of closures that are supported on in php 5.3+. Additionally, even php 5.3 is already several years old, there is little excuses not to use at least 5.3.
Some days, I even wonder if I shouldn't make PHP 7 a requirement, lol... But that's mostly because the Wedge userbase isn't really huge, so I could actually get away with it...
I just love using "$var ?? 1" instead of "isset($var) ? $var : 1"... Plus, the HHVM performance!