I often fly IFR in IMC at levels below the airways with a UK IMC rating without the benefit of any de-ice equipment. Freezing level at the flight planning stage and the OAT guage in flight are both considered rather important.
Returning to my home field for an IFR rejoin at (typically) 3000 feet I am often requested to 'climb 4000'. If the OAT is ner to freezing at 3000 feet I politely request 'wish to remain below 3000 due icing' and have never had a problem.
Without getting into another debate about the wisdom of flying in IMC without a radar service (I have long ago decided that I subscribe to the big clouds theory) do any more exzperienced forumites have any opinions on this? I would be especially interested to hear an ATC view.