Mine is due next month. My 2012 4/4 is now £165.00 a year from April so at under £14 a month I agree its probably not worth SORNing so I can keep the wheels turning.
If I had the last of the Trad 1600cc 4/4's 2017 onward the road would be £165 plus £320 for the first 6 years so at £485.00 I might give SORNing a bit more thought.