Googlemaps sat morning 9am
enfield to peaslake = 1h 15mins <-> 1h 40mins : Riding Good, lots of it
enfield to aston hill = 50 mins <-> 1h 5mins : 4~5 very short DH trails very good, XC very poor
enfield to Bracknell (look out) = 55 mins <-> 1h 15mins : Riding Reasonable lots of it
enfield to hadliegh = 50 mins <-> 1h 10mins : I dont know
enfield to thetford = 1h 25mins to 2hours : Riding poor, lots of it
enfield to north chilterns ( ie ashridge) : 40mins : Based on my experience of south chilterns Riding good but non-technical and difficult to find route without local knowledge.
Based on the above I’d probably check out Bracknell and chilterns if you dont know it.
Also remembered
enfield to wooburn = 45mins <-> 1h 5mins : no idea about riding.
Based on timings it would make sense to check this out