It can work (my current group has an erratic schedule but once a month seems like it will be the average). But I think it really depends on the players too. Do you think they will ENJOY an over-arching plot then by all means, do it that way. Or do you think they won't necessarily have the attention span for months at a time?
Random thoughts to consider that might help ...
1) Try and stop each session at an extended rest or, if not, then at a short rest and take good notes on stuff (like what dailies have been used, how many action points and surges remain for each player, hit points, conditions, etc).
2) Find a player (or two) that ENJOYS taking notes on a) NPCs and b) plot points, and see if they'll take the informal title of "NPC name note taker" and "plot point note taker" etc since they'll need to reference these notes a lot, esp for an interconnected campaign. Nothing fancy, just a place to keep track of names, major points, etc. Along similar lines, find a player to c) keep track of party treasure and dividing it up and keeping notes on where the "undivided" items (i.e. that strange mirror that emits evil radiation that you're hoping the local wizard can disenchant and then destroy) are - who is carrying it, etc... Special note -- Ideally, someone will naturally emerge and take this role(s) on their own without any word from you. It has less resentment if it was their own idea rather than a title that was given to them. So keep it rather casual if no one speaks up "hey, who is keeping track of the treasure" or "who remembers the name of the NPC you were supposed to deliver this too" etc.
3) Two days before the game session, consider sending an email recap of the last session. Nothing fancy, just a few lines or paragraph. That way, at the game table you can skim through the recap but you'll be able to spend more time on the current game session since everyone would have just read the recap a day or two before
4) If exp calculation takes ANY time at all, save it and send it as an email later. This way you won't spend game time doing calculations and you won't have players spending game time (or distracted) trying to level up characters
5) Schedules have a way of shifting, and the "social event that the child needs to go to at the last minute" often hinders "daddy's monthly game that he can do every month" so a week before (maybe when you send recaps) have a reminder about the day and time. By making it a reminder, it's also a passive rsvp since if it conflicts someone might remember to let you know. In a round about way, this helps on game day because no one is waiting for the player that won't show (past groups always had a habit of goofing off a lot until "that last person got there" often led to lots of wasted time until we realized that person wasn't coming at all)
6) Depending on your group's expectations for death/TPKs/etc , consider telling everyone to always have a back-up character ready (at least in basic ability scores, race, class) and keep that back-up character a level behind their main character (or whatever your rule is). Thus, if someone does have a character die, they can whip out their backup and use it as soon as there is a good spot to join in (as opposed to waiting to make it from scratch and then wait more to find a spot to join in)
....
I'm sure there are more things but that's what i can think of at the moment.
But, yeah, it really does come down to the players as to whether or not a campaign will work on that schedule.
You may want to consider starting the first two sessions as a way to test the waters... have the first two sessions some what connected, and see how glazed over everyone's eyes are when you try to get them to remember an NPC from the first session...
Or just ask them what they _want_, they'll be more receptive to a campaign if they make a conscious decision that this is what they want.
Anyway, just my rambles
