Is 91.175 enforced in the USA?

OK, see if I can get it right this time.
Chris wrote:
There is no problem setting up a descent to bring you under
cloud providing that whilst in cloud you remain 1000 feet above the highest
obstacle within five miles either side of your track and once through the
cloud are in VFR conditions.

The above cannot be done in the US. We can descend to the MEA (which is
published on the IFR enroute charts), or to the MVA (which ATC will
tell us) and if we are not in VFR conditions, then we have to do an
intrument approach. MEA's are higher than 1000 AGL I can tell you that.
MVA's are not published, but ATC has a map of them. ATC clearance
madatory for IFR flight (with one exception, Class G). I don't honestly
know what the rules are for descent in Class G with no radar and no IFR
clearance. I don't think there are any. It doesn't happen much, almost
all our IFR flight is with ATC clearances and frequently with radar as
well etc.