Do you have a Landmark? I just assumed you did, since this is posted under Lanmark. As far as I know, all the Landmarks are supposed to have a remote for the air conditioner/heater. I don't think the other models do.
If you do a lot of traveling in the summer, you might want to seriously consider getting that second air conditioner. We did after 2 summers without, it makes quite a big difference. Just spent a week at Myrtle Beach and we were very comfortable. Last year, we used a fan in the bedroom blowing right on us at night - helped with sleeping.