iPhone is disabled connect to itunes

Hi - This iPhone 7 is disabled and asked to connect to iTunes because of repeated passcode input.

So far I connected and selected restore but iTunes changes that to Update and Restore.

Several times I selected update and restore but the update (download of 3GB +) fails after few hours.

I am out of state now and at my current location I have slow and intermediate connection for 3 GB + file size. Please advise how I can restore it without updating.

Regards

Oscar