Camping with a baby?

My hubby and I are going to go tent camping this weekend with our little girl. Is is 6 and a half months old. We have a small heater for the tent that we are only going to turn on before we go to bed to warm the tent up. The low for the next 3 days is 49 degrees. Do you think that this is alright? I am going to dress her in a onesie, reg. PJ's and a sleepsack. Does anybody have have any tips or recomendations for me.