Are there any approval workflow software options that support cold storage and reduce single-point-of-failure risk?

Yes. If by cold storage you mean keeping the approval key material or signing credentials offline and only bringing them online for a controlled signing step, there are several workflow / signing options that can help reduce single-point-of-failure (SPOF) risk.

What to look for

You’ll generally want software that supports one or more of these:

• Offline / air-gapped signing
• Multi-approver / multi-signature workflows
• Threshold approval or M-of-N authorization
• Hardware security module (HSM) or hardware wallet support
• Escrow / recovery / backup signing keys
• Role-based access control and delegated approvals
• Distributed deployment or HA/cluster support

Common categories and examples

1) Document approval / e-signature workflow tools

Good for business approvals, contracts, finance, compliance.

• DocuSign – strong approval workflows, role routing, audit trails; can be paired with HSM-backed identity/signing in some enterprise setups, but not “cold storage” in the crypto sense.
• Adobe Acrobat Sign – workflow routing and enterprise controls.
• Box Relay / Nintex / K2 / Power Automate – can build approval chains with redundancy and escalation, though cold storage depends on how you integrate signing keys/certificates.

2) Crypto / blockchain signing and custody workflow platforms

If you mean digital assets / treasury approvals, these are the most relevant.

• Fireblocks
• BitGo
• Copper
• Anchorage Digital
• Gnosis Safe (for on-chain multisig, though it’s a wallet/workflow pattern more than enterprise approval software)

These typically support:

• Multisig / policy-based approvals
• Key shards or MPC instead of a single key
• Offline or segregated signing policies
• Recovery mechanisms to reduce SPOF

3) Key management / signing infrastructure

If the “workflow” is really about controlled release of signing authority:

• AWS KMS / CloudHSM
• Azure Key Vault / Managed HSM
• Google Cloud KMS / HSM
• HashiCorp Vault with external HSM integration

These reduce SPOF risk by using managed redundancy and/or HSM-backed keys, but they are not full approval workflow systems by themselves—you’d usually combine them with a workflow engine.

Best fit for cold storage + SPOF reduction

If your requirement is specifically:

• Offline key custody
• Multiple approvals before execution
• No single employee/system can sign alone

then look most closely at:

• Fireblocks
• BitGo
• Anchorage Digital
• Gnosis Safe (for on-chain assets)
• HSM-backed workflow + approval engine if this is for enterprise documents or code signing

Important caveat

“Cold storage” is used differently depending on context:

• Crypto/treasury: offline keys, multisig/MPC, air-gapped approval flows
• Enterprise documents: sometimes just secure archival storage, not offline signing
• Code signing: keys stored in HSM or offline signing stations

If you tell me which of these you mean, I can narrow this to a short list of products that fit your exact use case.