Turn on Windows Mobile hotspot remotely via Bluetooth

The following measures should help to keep the hotspot on:

• Ensure that the computer will not enter Sleep/Hibernate

• In Settings > Network & Internet > Mobile Hotspot, toggle off "When no devices are connected, automatically turn off mobile hotspot".

• Disable Wifi adapter power management options in Device Manager, expand Network devices, right-click the Wifi adapter, Properties, Power Management tab, uncheck "Allow the computer to turn off this device to save power", click OK

• For the Mobile Hotspot not to turn off itself:

  • In the Services applet, stop the "Mobile Hotspot Service" (icssvc)
  • In regedit, navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\icssvc\Settings
  • Create a DWORD Key named PeerlessTimeoutEnabled with the value of 0
  • Restart the Mobile Hotspot Service (icssvc)

  Alternatively, execute the following PowerShell command with admin privileges:

  powershell -windowstyle hidden -command "Start-Process cmd -ArgumentList '/s,/c,net stop "icssvc" & REG ADD "HKLM\SYSTEM\CurrentControlSet\Services\icssvc\Settings" /V PeerlessTimeoutEnabled /T REG_DWORD /D 0 /F & net start "icssvc"' -Verb runAs"
  

• If all else fails, this answer contains a PowerShell script to turn on the Mobile Hotspot if not enabled. You may save it as a .ps1 file and add it to the Task Scheduler so it runs every minute or so.
• Alternatively, you can use this solution instead, which is a small app that resides in the taskbar tray area.