Lots and lots o different options if you want to cross country...
Not a huge distance... all less than 8 miles
Pretty much it's gonna be past Emeric or Reymann. A lot of ways around there work...
done about 5 different ways... and there are many more that could be done
So... it's about what you want to see and how you can do cross country vs. trail...
and if you enjoy a bit of route finding for yourself and such...
With the trail it's about 17 ... which you could cut some by cutting up Dolly Dome area...
Since Vog to Merced via Fletcher is nearly all downhill... that half is fairly simple
and since u are advanced I would say you should be able to knock it off in 4 hours easily.
The second half is a nice stroll to start from Merced Lake thru Echo Valley before
you climb... from there it's a nice trail and ...
Well.. if you have the stamina... imo... you should do that trail... start early...
and take a long break in the middle of the day. 17-ish miles is not out of the ordinary.
And it sounds to me you will make a lot better time on trail.
Maybe come back another time and skip staying at the HSC and take whatever
time you need to do routes between the two...
That's my 2 cents.
Have fun