As long as you have a published instrument approach procedure, you can start the approach in any weathercondition (some states excepted, like the UK, I believe).. .You can continue the approach past the outer marker if the visibility is above the minimum required for the approach (typically 550 meter for cat 1).. .So in the sketched scenario, with rvr 1400 meter, you can continue the approach past the outer marker. Now, if ATC indicates that LVP`s are not yet in operation, you can only go to cat1 limits (typically 200 ft AGL).. .However I would be perfectly happy to do the approach to cat 1 limits under these conditions.