No internet provider anywhere can guarantee that service will never
be interrupted. Weather, equipment problems, network maintenance,
infrastructure damage and electrical interruptions can occasionally
affect connectivity.
If losing internet for several hours could create a serious
professional problem, a second method of getting online is sensible.
A Mexican cellular plan or mobile hotspot can provide one form of
backup when cellular coverage is strong enough at the residence.
Depending on installation conditions and the importance of remaining
online, a service such as Starlink may also be worth investigating
either as a primary connection or as a different type of connection
from a traditional wired provider.
Having two services that rely on different infrastructure can provide
more meaningful redundancy than simply having two devices connected
to the same home internet line.
Test the Backup Too
A backup connection is only useful if it actually works from the
residence. Test cellular performance inside the condo and verify
any installation requirements before depending on an alternative
service for important work.