Get one of these
www.amazon.co.uk/Hippychick-Mattress-Protector-Sheet-White/dp/B000CEQF8U/ref=sr_1_2?s=baby&ie=UTF8&qid=1326990556&sr=1-2
Life saver! We have this size, and it's fine for a single bed, as you lay it horizontally.
When it's wet, you simply change little man, and then, turn the sheet over... it's bone dry (turn duvet over). If he wets again... change little man and fold the sheet in half..it's bone dry (flip duvet upside down).. Just wash it in the morning on a quick 30 wash.
I would recommend underjams for sleepovers.. but, I doubt he'll have any sleepovers in yr 2 ( my daughter is 7 yrs in year 2)... they start to happen in yr 3 - 4....
underjams are big boys pants! the packaging is aimed to the older child...
my daughter would flood the bed every night... but, since turning 6 yrs (year one) - something switched on inside her head.... and we lift her every night - but she's dry every morning.
someone else mentioned not to carry him... and to actually wake him, and help him walk to the loo... that's what we do. most nights she's fine and willing... but, we had some awful nights when she would be upset and confused ... or would sit on the loo and not wee///// then, she would flood the bed! it drove me mad to be honest;.... but, i kept it to myself and just stayed calm and neutral.... and she got there!
get the hippychick mattress protector (flat sheet) - then, you're more sane from not having to 'change' entire beds during the night....
my advice would be.... go cold turkey now... no more nappy pants at night... and use the sheet.... continue limiting his drinks... no more after 5.30,
and, see how it goes.... that's what we did.. and it worked for us.
hope that helps
(sorry for random typing - this is the second time i've typed this out - as the page crashed and i lost everything i wrote! hence me typing quick and no caps!)