Pubs have suffered disruption and closures as a result of the travel chaos caused by the volcanic ash from Iceland.
JD Wetherspoon has closed all but three of its 27 pubs at UK airports.
Spokesman Eddie Gershon said: "We're just waiting for BAA (the airport operator) to let us know when we can re-open. What we're doing is redeploying staff in other pubs as best we can.
"Our airport pubs are important to trade and we're disappointed that they're closed, but it's out of our hands," said Gershon.
Geronimo operates three pubs at Heathrow airport: the newly-refurbished Tin Goose at Terminal One, the Three Bells at Terminal Three and the Five Tuns at Terminal Five.
It also runs the Betjeman Arms at St Pancras, the Eurostar terminal.
Operations director Ed Turner said: "We've taken nothing at the Heathrow Airport sites now for four days, although at the St Pancras site takings are 30-40% up on the previous week.
"We want to make sure our staff are positive and happy, and keep some salary in their pockets. We've re-deployed them doing staff training, additional spring cleaning, and handing out flyers, as well as getting out into our other pubs to better understand the Geronimo ethos.
"You've got to think positively, although the situation is a nightmare."
Elsewhere, James Nye, managing director at Anglian Country Inns, said the company accountant has been stranded in Morocco.
He was due to return to the UK last weekend, but phoned Nye on Monday morning to say he had been told the earliest he would be able to come back was 29 April. "We're looking at alternatives at the moment. It's the end of our financial year right now, so it's not a great time for him to be away."
• Have your staff been left stranded abroad? Or have you seen a sales boost from people stranded here? Let us know by emailing Gemma.McKenna@william-reed.co.uk.