The postings here highlight different attitudes to flying in IMC for long periods.
I know pilots who do it happily, so long as they are below the freezing level, even though they have no radar, and perhaps only a stormscope to indicate hazardous conditions ahead. This is not unreasonable in pure safety terms, because if you stay below Va, there should not be anything there that would cause a structural failure of the airframe.
I would not usually be so happy doing it (stormscope only) because it is only in a fairly narrow range of weather that you can be sure that nothing nasty is going to be hiding in there. Especially in southern Europe... also flying below the 0C level stops most IFR flight in the winter.
So I tend to use my IR mostly to climb to VMC on top, and the satellite IR images are priceless for this.
If one is going to penetrate something nasty, it is better to do so at a low level (and definitely below the freezing level).
I tend to find the freezing level forecast to be fairly reliable.