I have lots of experience of ski resorts, and I know Alpe D'uez. The Les bergers area of the resort is to the East of the village and about half way up the resort. It is a good 10 to 15 minute walk to the main village, depending on underfoot conditions, where all the action is. Alpe D'huez is a hilly resort and so you will have to walk down or up at some point.
In late March unless there has been late snow fall the pavements should be all cleared, but there is also a lot of melt freeze at that time of year and so ice can be a problem. I'm a bloke so cant really advise on clothing for the girls, but I would forget heels at all, and little plastic soled roll up flatties will be cold and have you on your backside in no time flat if it is icy.Wear your ski anorack for sure. In the clubs you will find people dressed all ways including the guy still wearing his ski boots and salopetes because he has never been back to his hotel. But as previously posted, a dress, or skirt and thick tights will probably be fine. I've always found a good bar with a band is better than clubbing every night, but it has to be done,at least once.Take plenty money, as you will probably get drawn into very expensive cocktails, and spirits When I was last there a couple of years ago there were only 2 clubs L'igloo and Les Caves. Both pricey but both used to have early evening prices to get you in, but then you spend more on drinks. If a load of you from the trip go as a group, you might persuade them to give you a group discount.
This is how I do it, Up at 8am, ski from opening of lifts to lunch time, beer, spag bol or soup, ski till lifts close, couple of pints, find out if there is anything interesting happening that night, back to apartment, shower, change, cook or go out to eat, pub, bed about midnight, (club twice, near beginning and last night usually. But just go with the flow. I go for the skiing not to party. Hope this helps.