It sounds to me like you are doing plenty and your heart rates sound great ! Just do both days at a conservative pace and see how much horse you have left afterwards. I would only ride once a day at most- your weekly milage is more than adequate for your goal, in my opinion. I would back off my riding 10 days before your event, also cut down on alfalfa & grain & any added oils. Just do a legging up ride 3 days before your event, maybe 1.5 hours of mostly walking. Good Luck !
