There are simply oodles of beautiful cottages waiting to be rented. You can rent a cottage in the UK for a weekend or for a month depending on your budget and requirements.
The first place to take a look is, we think, the English-country-cottages.co.uk website. They have a huge number of different sized cottages on their books, all over the UK. They should be able to meet your needs whether you need a place that will sleep two or twenty, take dogs, be near a pub or the seaside, have a pool or be near the town. The properties are all of a super standard and are extremely well equipped. It is worth noting however that in the peak season you will not be able to book more than one month in advance if you are looking to stay for just a shorter period.
Other good websites are cottages4you.co.uk and cottageholidays.co.uk. Again, properties are varied in size and location but all are of a good standard and are well equipped. You can again specify your requirements in terms of numbers of bedrooms, amenities and whether you want to take your dog with you.