Writing this because I came here to find this exact info and couldn't. So we did the walk in and camp option. Really lovely patch of grass just at Geldie Lodge (about big enough for a double tent without blocking the shelter). Walked in and put the tent up and then set off for the hills. From there back to Geldie Lodge it took us 6 hrs to do the two Munro's. Then we walked out the following day. As others have said when fording the burn near Geldie Lodge it's worth continuing up the bank a bit, you then cross both rivers in one.
Lovely loos at the Red House bothy if you can hold it in the next morning!