Taking your time and driving up through Wales would be lovely.
Take the M48 across the Severn Bridge to Chepstow (marvellous small town with a very good ruined castle). Then A466 up the Wye Valley with a stop at the ruined Tintern Abbey.
At Monmouth take the A40 to the food town of Abergavenny and continue through Crickhowell to Tretower with a stop for Tretower Court and ruined castle.
Now follow A479 and then A470 to Rhayader. Here you might want to stop off at Gigrin Farm for the Red Kite feeding centre. Feeding takes place 2pm in the winter, but 3pm in the summer months (when the clocks are on ‘Summer Time’).
Beyond Rhayader, the A470 takes you through the marvellous scenery of Mid Wales. There is little settlement along this stretch. At Caersws you have a choice of either staying on the A470 or or picking up the A483. The A483 is the more direct rout to Chester, taking you up through the Welsh Borders with Welshpool (close to Shrewsbury which is a nice black and white timber frame town), Oswestry with its ancient hill fort , and Wrexham.
The A470 is the more scenic route as it cuts across to Dolgellau (where the gold for the royal wedding rings was mined) and up through Coed y Brennin forest before dropping down through the Conwy valley a popular tourist area in the middle of Snowdonia with places like Betws y Coed and Llanwst to Conwy (walled town with an impressive ruined castle) and the Victorian sea side resort of Llandudno. Bodnant Gardens are close by. It is then a choice of the fast A55 to Chester or the slower A548 which takes you through all the seaside towns along the coast.
I haven’t attempted to break this up into days. I’ll leave that for you depending on how long you want to take on this. Remember there is little habitation or accommodation in the wilder bits of Mid Wales. This has only just scratched the surface and there is a lot more to do and see on the way. You might want to consider visiting Anglesey from Conwy/Llandudno. Snowdon isn’t far away. If you like preserved steam railways, there are two narrow gauge ones - Ffestiniog Railway which carried slates from Blaenau Ffestiniog to the wharves at Porthmadog and the newly rebuilt Welsh highland railway which runs along the flanks of Snowdon from Porthmadog to Caernarfon. Both run through magnificent scenery and are well worth considering.
If you want to know more about the slate industry, there is Llechwedd Slate Cavern in Blaenau Ffestiniog where you can take a trip deep into the ground and the Victorian slate workings. For the adrenalin seekers, this also has an underground zip wire - real Indiana Jones stuff...
