daxwax - In 1985 I faced the same dilemma as you, albeit without any EASA deadlines. One winters day in 1986 I gave myself the biggest fright of my life.
I set off from Southend in CAVOK. My destination was Haverfordwest reported as CAVOK. Enroute the weather deteriorated to marginal VMC. The next thing I remember was entering cloud and panicking. Although I had done 4 hours instrument flying in my ppl, that was barely enough experience to execute a 180 and get myself on a weather diversion to Cardiff, with reported better weather.
After that day, my mind was set on a instrument qualification to get myself out of any potential trouble.
As everyone has said here, it will make you a better pilot and I can thoroughly concur with that.