The curing agent (bostikure 1000) is the hardening agent and is compulsory if you want a good repair. Any one part glue will be susceptible to failure in high temperatures (eg. Summer).
Ensure that you mix the correct amount of hardener and apply 2 coats with about 15 minutes between, also make sure that you do not leave the lid off the hardener as the active agent will evaporate.There is obviously a load of other factors too but we are discussing the glueing here.
The use of a hairdryer to keep the temperature up would'nt go amiss either at this time of year, if you keep the components warm ie the tube and patch as well as the glue you'll stand a better chance.
If you want the best repair use the Bostik, tried and tested technology!
Give me a call if you need any more info 07915081041
Oh and before anyone decides that they disagree with the information i have given please note that this is merely my learned but somewhat humble opinion on the matter. Thankyou.