Its all pretty relaxed out there!
I have done lots of flying in Portugal.
I would head down through spain via Valadolid or Salamanca, then via CCS VOR into Portugal, that way you miss out all the high ground in the north (Serra d'Estrella) - mountain, about 6000 asl - probably spelt that wrong, then into mid-Portugal - fairly flat then!
Loads of airfields!
I would pop to LPSC (Sand strip about 700m) right on the coast (on the 317R / 17d from LIS VOR if I remember correctly) lovely beach!
Pop into LPCS Cascais and then either Portimao or Faro would be another nice spot! Or central Portugal try Evora (LPVR?) or Santarem (LPSR?) Nice places! (and airports)
Wouldnt go any later than July as it gets red hot! Im talking in the high 30's!
They also suffer from a lot of fog in the summer, but all clear by 1000/1100 ! sometimes a little hazy, but if your IFR, no worries!
Great ATC, very helpfull! English speakers all over the shop!
Landing fee's - cheap! So is the beer!
Have a great time!