Actually, this popular touristic place was my biggest disappointment in Peru. Firstly, even in a November, it was heavily overcrowded mainly by Latin American tourists but still expect huge lines of people on the entrance. When you got inside - it will be still crowds and to find a nice shot for a picture is not easy. Mosquitos are another big problem in MP. Take only long sleeve shirt!
There are plenty of mosquitoes up at Machu Picchu. Locals say they're not too bad and close to the river in the valley there are much more. Good news - this bugs don’t transmit Zika virus since MP is on altitude of 2800m but biting is extremely painful and could be swelling for a week or even longer. Train to MP is another challenge in Covid time since you must wear 2 masks + 1 protective face visor while you are in the train (trip tales 3 hours). So, it is very exhausting and you must consider this when plan the trip there.