Dear Blue Kangeroo
You mentioned
Tenerife in your posting, as the furthest you would like to travel.
Please do check out our guide to
Tenerife. Many hotels are happy to cater for special diets, as are restaurants, for example El Menor, a surprisingly cheap restaurant with a great atmosphere. Please also take a look at our
destination guides, for example, Menorca, Mallorca, Gran Canaria and Lanzarote.
I am unable to comment on the availability of dairy free/soya products in local supermarkets/shops but the following information may help your quest!
The Canary Islands have a long history of cheese making from Goat and Sheep milks. (Some people with an intolerance to cow's milk can tolerate goat and sheep milk, which is much easier to digest, but this is very different from a true allergy.) The most common of which is "fresco" (fresh), just a few days old, without too much pressing and drained on its own. It has a light, pleasant taste, slightly salty with an aroma of fresh milk, unlike the strong and 'goaty' taste which is often apparent in goat or sheep cheese in the UK. There is a large supermarket in El Corte Ingles (a large mall type center in Santa Cruz ).
Slightly more specialist holidays often have a much wider range of natural produce and can be more used to special diets, so the following may be useful...
EcoHotel la Correa, in Arona, Tenerife, located close to Teide National Park in a private estate provides a nutritional breakfasts of organic fruit, vegetable drinks, soya and rice milk.
Aparthotel Venus Albir resort, located in the village of Albir-Alfàs del Pi, near Alicante, with an award-winning Blue Flag beach, has 24 apartments using natural materials and solar power hot water system, an an organic restaurant.
We hope this helps your search. Do please let us know how you get on. This could be very useful for other families with the same issues.