We went to Nendaz end of January and had a great time. It snowed the week before so the conditions were great. We have three kids and the ski school up in Nendaz was excellent. The kids went in the morning and we picked them up after lunch. Nendaz is big enough for skiing a a couple of days but with the same lift pass you can see in Veyonnaz and Sivez, We rented a chalet further up from the main lift and it was very convenient with the ski bus stopping 100m from the chalet and took us to the main lift. The grocery stores are great and the italian restaurant was really nice in the main centre. I can strongly recommend Nendaz for couples and familes. Seems not be so well known to people but we had a great time. Swiss Air is flying to Sion from London in February and than you will have a 20min connection up to the main resort.