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 'backup power issue: 'Is there a way to access files offline, even if read only?' available: Yes.

The backup power 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 backup power issue yourself by looking for a resolution described in the article. If it is a complex backup power issue or you are unable to solve the issue, you may contact us by clicking here or by using other backup power support options.

For more information about resolving issues related to backup power in Quickbooks/QBO or to get support for the issue 'Is there a way to access files offline, even if read only?', click the link below: