Ferry routes/companies and prices

Having some time on my hands and trying to work out my options if we can travel abroad again.
I had a ferry booked Brittany ferries Rosslare to Bilbao 28hr crossing in November price for MH 2 adults and pet friendly cabin around €600 one way. But if you arrive in Spain by plane or ship you are required to to have a negative PCR check within 72 of arrival.
Checked Stena to Cherbourg around 18hrs dog in kennel or kept in MH as they don’t have pet friendly cabins, 2 adults MH outside 4 berth cabin about €340. The crossing without cabin was €240. So €260 saving but an extra 1000km drive. No PCR check required in Spain if you arrive by road.
Then looked at Stena and IF Rosslare to South Wales 4 hour crossing no cabin required for the short trip €250 with Stena €450 with IF again based on 2 people in MH.
At this point I couldn’t comprehend was Stena charge roughly the same price to go to wales as they do for a much longer trip to France. I also struggled to understand way IF was €200 more expensive for an almost identical sailing date and time.

It’s all a paper exercise at the moment as I can’t travel in Ireland. Traveling in France is currently prohibited for holiday purposes and in Spain even if you get in at the moment you can’t move out of state/County/Provence you arrive in.

As an aside my tescos vouchers get quadrupled in value in the ROI on Irish or Stena sailings. Not accepted on Brittany Ferries.

For those with a little spare time (48 hours) I have a lovely mostly toll free route from Cherbourg to Spain which involves two nights in France, NIGHT ONE and NIGHT TWO. The route has no issues even in mid-winter and both Aires are quiet and secure and close to the main route. By night three we are well into northern Spain.
From Cherbourg to San Sebastian being about 950km and using fuel at about 25MPG (about 11L/100km) @ €1.20/Lt will cost about €125. Add on the €26 toll on the unavoidable A63 south from Bordeaux and you have a total of about €150 against the €260 extra for the Bay of Biscay crossing.
While the price differential between the Cherbourg and the Bilbao/Santander route may vary significantly the overland route via France cost should only change with the price of diesel.

Interesting that you stop so close to Cherbourg the first night but I suppose it depends on your arrival time, my instinct would be to get close to the Loire on the first night be that Angers or Nantes or whatever route. A nice alternative nearby for an early stop is Fougeres if you haven't been before, free aire, really quaint medieval town.

https://www.campercontact.com/…a-carriere