I recently published an app named Unleash Your Formula. https://appexchange.salesforce.com/appxListingDetail?listingId=a0N3u00000MS8T1EAL
The app does something simple, it copies and syncs formula fields to the specified non-formula field (of the same type). This is an effective way to handle character limits.
Most character limit issues arise because the formula is referencing another formula, often multiple times, and each additional reference increases the formula character size by the size of referenced formula field.
With this app, you can reference instead the mapped non formula field, which will quickly reduces the character limit.
Even if you indeed have 5000 characters in a single formula, you can split it up into multiple formulas and use the same trick.