Blazor Server Recover App Data after Disconnect

Question

We have a huge form with hundred fields. If the user goes to fetch a coffee before submitting or saving it the SignalR connection may shut down and the entries are lost. Is there a good approach how to recover the data when the users clicks on the reload button?

I have tried the Circuit Handler but it seems more for statistics and logging. So far I could save the form data to session storage whenever a form value is changed. When the user reloads the page I could compare some meta data and if it's match restore the form data from the session storage.

Is there a better approach?