This very same issue - where Hotmail locks a mail account if the user is more that 300km from their 'usual' location - happened to my daughter only recently, when we travelled to Vietnam during the June/July 2016 school holidays.
Whenever she went to use her Mail app, her Hotmail emails could not be retrieved. Additionally, she would get an email sent to the account's 'rescue email', saying that the account had been locked for security reasons. She got a new email each time she move to a new city during out trip.
As soon as she was back in Australia, the account was 'unlocked'.
Unfortunately, there currently is no easy way to prevent this from happening with Microsoft accounts.
Your best bet is to set up another email account with a provider that doesn't suffer this issue - I haven't had any problems with my iCloud account during overseas travels.
Then, before you go away, just auto-forward your mail to that other account - so that you can still access your mail if the other account gets locked out.
Here is an article on this topic, discussing the problem and ways to work around it.
How to Avoid Getting Locked Out Of Your Email When You Travel - Forbes