He was arrested after officers viewed the hotel's CCTV footage, the Telegraph reported.
Fergus admitted driving his $117,600 BMW on the B864 Kinloch Rannoch to Tummel Bridge road while twice the legal alcohol limit (43 mics).
The retired chartered surveyor had previously been of good character and was a senior committee member at his local rugby club and a member of the fundraising committee for a local school for disabled children.
Fergus, from Troon, South Ayrshire, admitted behaving in a threatening and abusive manner towards staff, wilfully destroying property and drink-driving.
Ruth Fergus, 69, admitted causing fear or alarm at the hotel by threatening guests and staff with violence.
The couple were fined $7400 and Robert Fergus was also ordered to pay the hotel $1448 compensation to cover the cost of the damage. He was also banned from driving for 12 months.
Solicitor Ewan Cameron told the court his client had "consumed much more alcohol than was sensible" and reacted "disproportionately" when he confronted reception staff.
Pauline Cullerton, defending Ruth Fergus, said her client had eaten little during the day and so "reacted badly" to the alcohol she drank.
Sheriff Gillian Wade told Robert Fergus: "I don't think I need to tell you it's a very sorry state of affairs. I have no doubt you will regret it for the rest of your life."
The MacDonald Loch Rannoch Hotel, which enjoys views of the loch and is close to Cairngorms National Park, prides itself on offering "a tranquil, authentic Highland retreat".
It says: "The magnificent setting is the ideal location to enjoy a break away from busy lives or a romantic retreat."
There are also several whisky distilleries at hand for guests to visit.