I haven't stayed in that particular hotel, but have used many Premier Inns, and they all seem pretty much of a muchness. If you're booking a family room, you'll have a double bed and a double sofa-bed - I don't know the ages of your children, nor how many - and an en suite bathroom with loo, sink, bath and over-bath shower. Towels are provided, as is soap, but IIRC it's that Dove liquid soap (personally, I hate the smell of it) and it'll be in a squeezy tube attached to the wall. I have weak wrists and find it difficult to use, so it might be an idea to take along a bar for your DCs.
There will be a similar tube on the wall by the shower.
There will probably be a chain pub/carvery close by or attached, which will be fairly family-friendly, and will usually have high chairs available. I cannot speak for the cleanliness of same, but in general, staff are friendly and helpful if somewhat informal. There will probably not be any babysitting/listening services, but there may be a small play park close to the hotel.
For a budget chain, I have usually found PI to be clean, warm and dry, with working facilities and care taken over windows not opening too far etc. However, the rooms are not huge and I wouldn't suggest spending too much time in there with LOs - they're basic, and that's what you're paying for.
Hope this helps - I see you've posted at least three times!