....easy enough to book campsites near the route
We have thought about it as a nice easy accessible trip from home and would camp, so interested to know where you stayed.
When I did it, I stayed at the following:
Day 1:
https://www.strava.com/activities/7398851587Train from Chelmsford to Ashforsd Intl. (make sure you note where the accessable carriage is on the display boards to get to the correct end of a very busy train service!)
Birchington, overnight Hawk campsite (£19/night) with pre-camping drinks at Wantsum Brewery and a none Cantii route bridleway to the camp site. Evening meel at Minnis (ok, but not great). Nice micro-pub in town.
Day 2:
https://www.strava.com/activities/7403659233From Birchington to Capel-le-Fern with some route modification to take in the Spitfire museum at Marston (free entry & cafe on site) - road quite busy around there though. Lots of additional good off-road added to museum and near Dover. Long drag up out of Dover. Overnight at Little Satmar campsite, (£19/night) only 2 dinner options (other than a pot noodle at the camp site) The Valant Sailor (closes early, further away from campsite) & The Royal Oak, very trad pub, super cheap (massive plate of food and 4 pints, £16)
Day3:
https://www.strava.com/activities/7410027648Capel-le-Fern to Rye Foreign Overnight at Hare & Hounds, just outside of Rye along A road up the hill £12/night
Day4:
https://www.strava.com/activities/7414615974Rye to Westwell
Good off-road added not on Cantii way to get down from RF to Rye
Overnight on the NDW at a small campsite Dunn Street Farm, £10/night no local food places, so needed to picnic based on buying food in the co-op in Wye.
Depending on how you slice & dice the route there are other camping options, Kingsdown is very popular for example. Needed to book a week or so in advance, I left it to the week before and had to ask by email directly to get on the Hawk and Hare sites as online they were showing as full but they were able to squeeze a 1 man tent on ok.