Do this outside CAS in the UK with some form of radar service & and make sure you have a rock-solid legal alternate in case the Wx deteriorates & you need to divert.
I am not sure where a radar service comes into it. You don't need that to get back down, either OCAS on a made-up letdown, or to fly an IAP.
Re your other Q about getting stuck above a layer, of course it can happen; wx is not 100% predictable. What one does is make sure the tafs and metars for the destination are SCT or better. IF this fails (and I don't recall it ever failing for me, largely because most of my long VFR trips were to warn southern countries) the official legal procedure is to declare an emergency and ask for the IAP.
There is an "unofficial option" which is safe at coastal airports where there is a way to descend OCAS over the sea, and then call up the airport when under the cloud, and I believe this very obvious method is a national past-time in countries which don't have the IMCR.
Re the other man's comment, the alleged hostility to the IMCR abroad is far less than claimed. Most GA pilots would give an arm for it. France has just announced its own "IMCR", in a finger-up to EASA. The official resistance to an "IMCR" is simply that it is perceived to undermine the IR which, along with vital capabilities like goolies dangling very symmetrically, has over the decades become the gold standard for "professional pilots". The IMCR is virtually an IR, except for Class A-C and needing 1800m vis, but is much more achievable, and if it became widespread, the airline pilot unions would go berserk because of the perceived undermining of the 14-exam CPL/IR to which their member status has been (inexplicably) nailed. There is no safety case underpinning any of this; the IMCR has a superb safety record.
I probably owe my life to my ex-airline captain instructor, who somehow managed things so that the vast majority of my IMCr training was done in actual IMC.
I don't think you owe your life to anybody in particular. If you have a license privilege, and you are unable to use that privilege, but you feel you need that privilege, then you need to do something about it. The IMCR is just another privilege which, if properly trained and maintained current, allows you to fly any IAP in IMC, and legally so in the UK. Had you got an IMCR but could not do this with it, but somebody passed you on the checkride, you should have asked for a refund
BTW you can land at Luton, Gatwick, Stansted, London City today, with an IMCR, as they are all Class D. They just cost about £500, and LCY does not allow GA anyway. Heathrow is Class A so you can't go there (and they don't allow GA also). The 1st 3 are perfectly doable with something like 24hr PPR. The PPR and the £500 make sure these airports are closed to GA even if there is nothing going on.