EnglishAl
You should see the kit on one of the aircraft I flew commercially in the airways. Best I had was a KNS80. Few self-respecting owners of an airways-equipped aircraft would get airborne that ill-equipped!
IO540
Radar? Radar? Oh, the luxury. OK, one of them had a Stormscope, but no functioning weather radar in any aircraft I flew in the airways. I have never had a problem descending to clear icing conditions, and it was always a commercial decision as ice was affecting speed more than the benefit I was getting from density altitude.
An aircraft with no de-icing kit is more vulnerable, but that just means a decision before departure and more caution after making a marginal decision. It does restrict options but only in terms of timing and having to be flexible. Most of the year it should not be a serious restriction.