5 days! Are you sending it by sea?
Certbot doesn’t have any mode of operation that would allow a pending authorization to get reused. Most ACME clients don’t.
Off the top of my head, one that does is Posh-ACME: https://github.com/rmbolger/Posh-ACME/wiki/(Advanced)-Semi-Manual-DNS-Challenge-Validation . You should be able to come back to it after 5 days.
screen is a good suggestion.
Another one is to permanently delegate your _acme-challenge. subdomain to a second domain using a CNAME record, and host that second domain’s DNS somewhere more sane.