Are the red spots at the edges of the fins?
Unfortunately, with such a deadline and cost.. unsure what you can do. Are you going to be able to take him with you? You can try the ich medication now and hope it's gone by the time you have to leave.. then pray he is fine when you return.
I know you want to save him, and if it's possible, then sure.. but if you can't take him with you, all you can do is do medication until the night before you leave- then just do a 100% water change and just add in water conditioner. Don't feed him before you go, and don't use vacation feeders- he can easily go a week or two with no food. And just hope that what he has will allow him to hold up until you return. How long will you be gone?