Our family of 5 - 2 adults, 2 teenagers and one 11 year old have set our itinerary through Vietnam and also Siem Reap...now for the accommodation.
I have been reading posts and info for months but am still unsure as to what is the most cost effective way to book accom.....myself before we get there, a viet agent or just wing it and find something when we get to each new place (would this option be viable mid December to mid January?).
We will be there for about 25 days, we will be on a budget for accom for hopefully less than $150 (am I dreaming) per night (way cheper if possible in some places), would prefer family rooms but prepared to split into 2 rooms in need.
Thank you in advance.
You'll have no problem finding accommodation for much less than $150 per night (for $150 a night, you're into 4 star territory; if you're happy with a 2-3 star equivalent, you won't spend anywhere near $150).
With respect to finding big enough family rooms, I can't really say (I never look for them, although I did end up staying in one by chance once on Cat Ba - that was only $10 a night).
As it sounds like you're prepared to be flexible (and take 2 rooms rather than a family room) you should have no problem finding accommodation when you arrive, although if you've got your heart set on one room large enough for 5 people, you'll probably need to research hotels in advance, as I don't think there are that many of those around.
Hopefully someone who's traveled around the region with a family can give more specific advice.
If you plan to stay in popular Vietnamese holiday spots you will find lots of incredibly cheap rooms with ensuite and about seven beds for as little as $10 a night, the Vietnamese travel with the whole family so this style room is quite normal here. Mid-budget most three star hotels have family suites for around $50-70 a night, for $150 a night you could get a self catering apartment in some places or a couple of interconnecting rooms in a resort. Most three star twin rooms (around $25-40) are large with two double beds, the hotels are usually quite happy to supply an extra single bed (usually about $15) if you struggle and don't mind bunking up together.
If you have definite dates planned for each place it wouldn't hurt to try and pre-book at least one night of your stay, Dec/Jan is peak season so it would save you dragging tired teens around in the search for accommodation and give you more time to enjoy your holiday.
While it's quite easy to find rooms with two double beds or other so called 'family' rooms (for example, Art Hotel), with 2 adults and 3 children of 11+ these sort of rooms are likely to be a bit too cosy! However, as LolaNguyen says, some places have interconnecting rooms, so that might be your best option - then you get two bathrooms and a bit more space. A couple of places in Hanoi that I know have interconnecting rooms are Hoa Binh Palace Hotel on Hang Be (not cheap but within your $150 for two rooms), and I think Asian Ruby Hotel on Ta Hien and Classic Street Hotel do as well, but I'm sure there are others. I'll let you know if I remember any others. Triple rooms are common too so even if you have to have two separate rooms you can have the kids in one and you in the other, and with many hotels only having two rooms on a floor you can have the floor to yourself.
May de Ville Hostel, just off Ta Hien, doesn't have interconnecting rooms from what I can remember, but it has some communal areas with TV and a pool table, so somewhere for the kids to hang out. A double and a triple there will cost around $70.