Hi Germarchip.
As you no doubt know, the recommended interval is around 60k miles (100kms). In theory then, it should really last
comfortably past this point without risk of failing unless you are very unlucky - there's always a good safety margin built in to these figures.
However (!), it really isn't going to make much financial difference - in the scheme of things - whether you get it done today or in 6 months time as it won't need doing again for many years (perhaps never again...

!)
If you have a garage doing the normal servicing for you then, personally, I'd ask them to do it when the next service is due this year. Labour costs are usually less for each item the more you are getting done at the same time!
If you DIY your servicing, and also plan to DIY the cam, just do it whenever!
Oh, and worth doing the tensioner and spring too. (My garage was happy for me to source the parts and when I told them I could get it all for £50 reckoned it was much less than they'd have paid for them! Labour cost is around £100 for the job.)