QB Issue Resolution:

Not really, but if / when my wifi goes out, I just turn on the hotspot on my phone.

If the power goes out, you’re ok until your battery dies.¬†¬†There are backup power supplies you can get.

Resolution for Issue 'Is there a way to access files offline, even if read only?' available: Yes (Solved).
Source: Intuit Community forum.

Is there a way to access files offline, even if read only?: this issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for backup power
Quickbooks Repair Pro will resolve it efficiently and affordably. Guaranteed resolution of your issue, or you pay nothing!

Error Recovery for backup power [Canada]
E-Tech is the #1 Quickbooks data migration and Conversion service provider.

Get 50% off Quickbooks Online

Click Here for 50% off!

Additional Support Options: