From the rest of Europe / International:
The travel options internationally are numerous
Car - Car travel in France is easy, with a good network of motorways and dual-carriageways as well as very pleasant trunk and main roads. There are large chains of travel hotels and lots of local B&B and smaller hotels on route if you wish to break your journey en-route, but with the excellent motorway network, Germany, Belgium, Holland, Italy & Spain are within a days drive. There are regular comfortable clean rest-stops - many of which have children's play areas - swings, slides, zip-wires (as well as food & fuel).
Flying - Within Europe Brest, Rennes & Nantes are all well connected, they also are well connected across Europe, with Nantes and Rennes being long distance hubs. Car hire is available at the airport - in peak times it is sensible to book ahead - and it is possible to request car seats.
Flying - Long Haul / International - The commonest way is to fly into Paris, from which you can easily connect to the TGV high speed rail network that serves Brittany well - with Paris - Charles de Gaulle / Roissy Airport its possible to catch the TGV direct from the airport hub. If flying into Paris - Orly airport you need to take a cab to Massey TGV station or high speed underground (Called RER) to Gare Montparnasse or bus transfer to Gare Montparnasse - which might be more difficult with young children.
Train - Paris is just over 2 hrs from Rennes by TGV and car hire is possible in Rennes - We are about 90 minutes from Rennes by car. Both Rennes and St Brieuc (half an hour from us) are connected into the SNCF network
The commonly used options for travel from the UK;
There are two options from Ireland:
Les Gites du Sanglier
Poulancre d'en Bas, 22320, Saint Mayeux, France
0033 (0) 296 Twenty-Four Fifty Thirty-Nine