In theory it is possible to remain on UK plates for a year,
1. Saga Insurance (if you're old enough) offer 12 months driving abroad, and as far as i'm aware, no restrictions ie for a maximum of days in a single trip (like 90 with some), but you have to be resident in the UK at the time of purchase.
2. MOT? You can retest your vehicle just before you leave and if it still has remaining MOT you can get 13 Months before next test.
3. Luckily you can now buy vehicle excise duty (road tax) online, you will still need this although you are not in the country because without it you would have to SORN the vehicle, effectively confirming the car is "off the road", which could bring up insurance issues should you be unlucky enough to claim.
4. If you take your car for longer than 12 months it is classed as permanently exported, worth mentioning but i've not heard of any issues about this, i'm unsure if Border Control,DVLA,Vosa keep exit checks anyway.
5. Enjoy the journey whichever route you choose, take your time and plan ahead. Take a recent European road atlas and don't believe everything the Satnav says!