He's definately not too young to be without Mommy for a few days, and probably won't miss nursing when Mommy isn't there and it isn't available.

Actually the person who will have the hardest time with this is Mommy. I know it's always been that way with me and my sisters and all my friends. You and munchkin will probably just be too busy (and you'll probably be too tired) to worry, and if he's missing Mom, 2.5 year olds are pretty easy to distract with playing outside, a visit to Gramma or a special treat.

Mommy on the other hand is going to be going through some serious withdrawal, so be gentle with her if she calls 4 times in the first 2 hours and once every 2 hours after that. It's not that she doesn't love you and trust you, it's just really, really hard. (And if she doesn't call at all, buy her a present, 'cause she really wanted too but toughed it out instead!)

You're a grown up and you'll manage the practical stuff, you may not do it exactly the way your wife would, but that's why you're the Daddy, and she's the Mommy. Once when my sister got home from being away for a couple of days, her daughter's cloth diaper was fastened with duct tape. My brother-in-law had poked himself with the diaper pins once to often and said the-heck-with-it. It wasn't what my sister would have done, but it worked and nobody got hurt, which is the important thing. (If you knew my brother-in-law, you would probably say was the only thing!)

Have fun, you'll do great!

(And seriously, get Mommy a present or pick her some flowers or whatever the tradition in your family is for when someone has been a very good grown-up, for when she gets home to show her that her men missed her too!)

Speaking from personal experience I would say that the perfect opportunity has presented itself to you. I would encourage you to use this time to build upon your already close relationship and enjoy your time together. Its a great bonus that you have grandma just nextdoor too! Just take some time to discuss with your wife the points which you feel may worry you, and even note down somethings which you feel you may forget when left to your own devices.

Depending on how advanced your communication is with your little chap you could even start talking about the "fun home alone" adventure you will be having together.

While I am not particularly fond of buying and talking about gifts to children as a form of comfort, this is one occasion where I have gone ahead and done that...and it had a really good effect, also for me...I always felt good coming home with a small gift for my daughter.

Ps; Try and get all the bits and pieces you may need ready beforehand, and make sure you know where things are stored. Decide how you will manage your food arrangements and get help if needed.

Enjoy!

Not only will they be fine, but IMHO if you're at all anxious about it, you must do it, if for no other reason than for all parties to overcome their fears about it. IMHO, 2.5 years is too old for a parent to never have spent a single night away -- it's an important step for the development and independence of both the kid and the adults.

Also, consider a few days as critical practice and conditioning. Things happen in life, you can't always control parents having to be away, so you may as well get practice with a non-threatening and short absence. To wit:

When my son was a little more than a year old my wife had a serious illness and needed to spend most of a year in and out of the hospital, typically for several weeks at a time. (Don't worry, she's fine now.) Son came through well adjusted and with a great relationship with Dad. But it would have been a lot more traumatic if he and mommy had never been apart before that. My wife had taken various short business trips, a few days here and there, and we were very thankful for having had the preparation.

The best advice I can give is that if you treat mom being away as a normal event, the kid will likely take his cue from you. If he sees his parents approach it with anxiety, so will he.