Your school district is obligated to provide homebound instruction for students who cannot attend school. You need to contact the special education administrator in your district and request a meeting and ask that the nurse be present at this meeting. You will need to bring all of the relevant medical information with you information.
The school should draw up a health plan and either an IEP that specifies home instruction, an health plan that specifies home instruction, or a 504 plan that specifies home instruction.
And yes…1:1 instruction can keep a student up for an hour or two a day. Usually only one or two subjects are addressed. Remember, this will be the ONLY student present.
I would wager a weeks pay the folks providing home instruction are not volunteering to do so…they are being paid. They are being paid to deliver the course material to your student.
Colleges are very understanding of medical disruptions in school.
Your son has some significant medical issues…and is presumably under a doctors care. Do you really think going to a different country is a good idea?
What are you asking the school district to provide? Have the agreed to a home instruction plan? Has this been written up? WhT are the accommodations IF your son is unable to do the work from time to time. Those accommodations need to be part of the plan as well.
You have been give some good options on this thread but it seems like none of them are what you want.