Canopies can descend in holes with a circumference far less than that required for an aircraft. So in theory a 900ft cloud base is not a problem as long as there is a hole for them to descend thru.
Realistically, though, would such a hole be large enough for an IFR aircraft on approach to look up, spot the chute, get out of the way, and then continue the approach?
Two or three canopy diameters? I don't think so.