An expandable packer or anchor is disclosed. It features a gripping device integral to or mounted in a sleeve over the mandrel and mating undulating surfaces to help maintain grip under changing load conditions. Upon expansion, pressure on a sealing element is enhanced by nodes to increase internal pressure as it engages an outer tubular. Adjacent retaining rings limit extrusion and enhance grip. A gripping device, such as wickers on slips, preferably digs into the outer tubular. The expansion is preferably by pressure and can incorporate pressure intensifiers delivered by slick line or wire line. Release is accomplished by a release tool, which is delivered on slick line or wire line. It stretches the anchor or packer longitudinally, getting it to retract radially, for release. The release tool can be combined with packers or anchors that have a thin walled feature in the mandrel, to release by pulling the mandrel apart.