[M T]

  Audio would be tricky, but if those city tours can get it done there is a way forward with either headphones for everyone or a amplifier for the teacher.   

(AIUI, the camp with the 82 cases is a week-long (sleep-in) camp.  I think I saw their cases went home to 10 states.)

Earlier (a month ago) I posted a picture of standardized tests being done spread out across a soccer field.

As for classes, the audio would overlap from the different classes, but something like Zoom should allow each student to have good audio, and to minimize any audio from neighboring classes.   It could be used on laptops, tablets, or smart phones.
But, you aren't going to have your chemistry lab, computer lab, cooking, etc. outdoors because the equipment isn't appropriate outdoors.

We in California are so spoiled by our weather, we think this is possible.  Everywhere will be a problem if the sun is shining (threat of skin cancer, sun burns, ...)  I can tell you that it isn't possible in the south due to the frequency of storms (rain, wind, and lightning) and/or the heat & cold, and it isn't possible in the north because of the cold temperatures and snow.   Once you have a roof overhead (solar panels as you mentioned) and partitions, you're getting back to being indoors.

Instead, I could see being indoors, but on an exterior wall, with large fans that replace the air at a measured pace.   I'm pretty sure you could avoid rain getting in, but the problems will be controlling the temperature (and, to a lesser extent, the humidity).   Wow, it is beginning to sound like my elementary school, built post-WWII (E/W single-floor rows of 1x6 classrooms, 15' high. Grass area between rows. N wall was all window. S wall was outdoor covered walkway (no windows).  Several large (3-4') fans.  Heating units overhead.   No A/C until probably the late 60s (in coastal Texas).

But, getting that in place quickly can't happen.  Budgets are already set.  Supplies would be limited.  Buildings can't be redesigned.

[M T]

  Audio would be tricky, but if those city tours can get it done there is a way forward with either headphones for everyone or a amplifier for the teacher.   

(AIUI, the camp with the 82 cases is a week-long (sleep-in) camp.  I think I saw their cases went home to 10 states.)

Earlier (a month ago) I posted a picture of standardized tests being done spread out across a soccer field.

As for classes, the audio would overlap from the different classes, but something like Zoom should allow each student to have good audio, and to minimize any audio from neighboring classes.   It could be used on laptops, tablets, or smart phones.
But, you aren't going to have your chemistry lab, computer lab, cooking, etc. outdoors because the equipment isn't appropriate outdoors.

We in California are so spoiled by our weather, we think this is possible.  Everywhere will be a problem if the sun is shining (threat of skin cancer, sun burns, ...)  I can tell you that it isn't possible in the south due to the frequency of storms (rain, wind, and lightning) and/or the heat & cold, and it isn't possible in the north because of the cold temperatures and snow.   Once you have a roof overhead (solar panels as you mentioned) and partitions, you're getting back to being indoors.

Instead, I could see being indoors, but on an exterior wall, with large fans that replace the air at a measured pace.   I'm pretty sure you could avoid rain getting in, but the problems will be controlling the temperature (and, to a lesser extent, the humidity).   Wow, it is beginning to sound like my elementary school, built post-WWII (E/W single-floor rows of 1x6 classrooms, 15' high. Grass area between rows. N wall was all window. S wall was outdoor covered walkway (no windows).  Several large (3-4') fans.  Heating units overhead.   No A/C until probably the late 60s (in coastal Texas).

But, getting that in place quickly can't happen.  Budgets are already set.  Supplies would be limited.  Buildings can't be redesigned.