With Quinn's current contract the Rams are scheduled to pay Quinn $11.4M in 2018 and $12.9M in 2019. [
overthecap.com]
(Note that Quinn's cap hit for 2018 is $12.4M because it includes $1M in pro-rated bonus money.)
Are you suggesting the Quinn reduce his 2018 salary to $3M to $4M in exchange for ending the contract after the 2018 season? That's what it would take to reduce Quinn's cap to the $4M-$5M range for 2017 and make him a FA for the 2019 season. I can't figure out why Quinn would do that ...
AlbaNY_Ram