Had fostered 1 rescue cat with 4 of her kittens (around 8 weeks old) before. As they were from factories areas, there were a lot of mites and ticks on their body and inside their ears. In order to prevent my own house cat to get infected as well, we isolate this family from my cat. The ear of the kittens looks exactly the same as the ear of the kitten shown in the picture.
Since the vet is close for the weekend, and we need a temporary solution (seems the same as yours, as your kitten will only be visting the vet after a week)
The temporary solution before visting the vet:
My mother used some tick comb to remove the ticks on their body, and
used cotton wool dipped with a bit of Sesame Oil to wipe off the
mites inside their ears (Noted: Just use a little of seasme oil will do, else your cat's ear will be very oily; No worries, the smell will wear off after few days). Using of sesame oil is not an old myth as it
really works perfectly! Though I am not quite sure of the real reason
behind, but my mother explained that the reason of using Sesame Oil is
because bugs such as mites and ticks "dislike" the smell and will
"flee" away from the area.
We brought this family to the vet for health checks and vaccination
before bringing them to the shelter; and the veterianarian give them
some ticks removal spray to fully remove the ticks and the eggs of the
ticks from their body. However I am not sure if the tick removal
spray is applicable to your kitten as it has upper respiratory
infection. It is still the best for you to consult your veterianarian.