Enter Schengen before D7

Hello - Dilemma and rules - ok so my D7 is future dated and I have to drive slowly with my cat - I have contacts and friends in France. Can I enter France as normal tourist ( not been in Schengen a time in last 6 months) stay for a few weeks or couple of months ( in my 90 day limit) then drive straight to Portugal to trigger my D7 by its start date ?