What do the contracts with your suppliers and the policy with your insurer say?
Changes in government regulation do not ipso facto relieve Parties of the obligations under a contract under common (English) law. Contracts are allowed to allocate the risk of force majeure (and indeed, to define it because it has no common law meaning) but if they don’t, then each party bears their own risk and if they fail to honour their obligations they are in breach of contract.
Common law does have the doctrine of frustration, however, that is much narrower and must result in the inability of the contract to be completed at all.
And then there are consumer rights which may apply.
When the dust settles, we are likely to see a lot of litigation around force majeure.
Your venue appears to be complying with both the law and their obligations under the contract so you have no breach of contract claim against them and no trigger for the insurance policy. If you choose to cancel, then you broke the contract.
Importantly, the position is reversed in civil law jurisdictions - a party unable to fulfil their obligations under a contract is not in breach.