Personally I book 1 hour max, I get my fill of sex in that time and am not interested in paying a prossie to talk and have drinks on my time.
When you say 4-5 drinks max what drinks do you mean ? If alcoholic you might end up with a pissed prossie on your hands in the middle of a hotel
. Whatever the drinks, that will be a fair proportion of your 4 hours just sitting, drinking and presumably chatting. If you have sod all in common it could be excruciating.
If you are looking to role-play or have a GF in the prossie, hence your idea of a long booking etc, I would go for a shorter booking first to make sure you can stand each others company.