Writing objects to PROGMEM

Question

A few days ago I encountered memory problems (SRAM shortage) on my Arduino. I've read a lot and fixed the problem, now I have around 900 bytes free in SRAM. However, I still have difficulties understanding and using progmem.

The user is allowed to create up to 10 programs (a program in my case is just some object storing the user's preferences). As I don't want to run out of SRAM, I planned to store them in PROGMEM.

Consider the following class:

#define MAX_PROGRAMS 10
#define MAX_PREFS 10 

class Program
{ 
  public:
    Program(String name, Preference* prefs[]); // ctor

    String getName();
    static byte getNoOfPrograms();
    static Program* getProgram(byte idx);

  private:
    const String _name;
    static int _programCtr;

    Preference* _preferences[MAX_PREFS];
    static Program* _programs[MAX_PROGRAMS];
};

One notices that a program can store up to 10 preferences, hence, if the user decides to make 10 programs, each with 10 different preferences, we will definitely run out of SRAM.

Therefore, can I store instances of the above Program class in PROGMEM if I define them as below?

const Program* const pgm PROGMEM = new Program(F("Test"), ...);
// ...
delete pgm;

I presume this is possible since the whole object is const and could never be changed. I actually tried this and had no compiler errors, however, I was stumbled by the fact that the above two lines of code use 22 bytes of SRAM, when I expected it not to use any.

In my case, would it be better not to store the whole object in progmem but only its constant fields, and do the same for all constants in Preference ? (i.e. change const String _name to const char name[] PROGMEM; etc.)