I have a walkout basement unfinished.  The exterior wall has a door that opens outwards to the outdoors.   That framed wall with the exterior door  has been insulated, dry walled, and painted.  The rest of the basement has  concrete walls and concrete floor.  I want to insulate the basement.  For the concrete floor I want to put down 1-inch rigid foam insulation and in two layers of 1/2 inch plywood, followed with flooring.  My issue is the bottom of the existing interior door is 2 inches off the concrete floor and one and three quarters with the bottom weatherstripping.   So, my door is not going  open to the interior – it will be be blocked by the flooring.  What would be the easiest way to handle this?  Could I order a shorter door and fit it in the existing framing without any major modifications Other than increasing the height of the threshold?