why's it matter if you're 50 when others are 70? i mean, you're ~40 and everyone else is 60...doesn't hurt your gameplay that much. anyways, the people who are 60 now..*most* of them have months and months of raids on you, meaning they have far superior gear than you'll have at 60 and it will take forever to catch up with that and you won't make it by x-pac time. so, with their better gear they will level faster than you when the x-pac comes so you'll still get behind, probably be around ~64/65 or even as low as 63 when they're 70, especially because they're hardcore raiders and have gone from casual to hardcore gamer.
but if you absolutely *have* to then yes it's possible but you won't have much time for fun stuff which takes months if you truly enjoy the game for all the dungeons and unique quests spread throughout all levels. just quest your heart out and grind when you're out of quests on humanoid mobs to get the most gold for your time unless you're a skinner. especially with christmas break if you're like me you'll be playing 12+ hours a day, although i play 12+ hours a day anyways cuz i'm internet schooled. (lol you said christmas break and i took it as you wont be able to play while on break, because i play all the time when i'm not on break, so my break is a trip somewhere where i cant play)
hope you reach your goal if you do set it as your goal