The possibilities as regards the reasons for these symptoms are several. If the symptoms are truly intermittent and he return back to normal, it could possibly be episodes of TIAs (transient ischemic attacks) which is a sort of brain angina. It would obviously mean that he is at high risk of developing a fresh stroke and you need to get a quick work up done for this. Another possibility is peripheral vascular disease if the symptoms are in relation to a particular limb. Obviously you need to urge him to get rid of the addictions, more so the smoking. Nonetheless, these symptoms can be due to other causes such as peripheral neuropathy due to vitamin B12 deficiency which is common in chronic alcoholism, especially if they are not intermittent and reversible.
im 36 from u k have same symptoms not had a stroke but everything else same my gp says its perphial neuropathy i had drink problem up until i got diagnosed 5 months ago still had no scans just blood test now have no feeling up to my chest and my doc says see him in six month by which time i doubt ill be able to walk . hope things turn out ok 4 you and your husband ,its a long road but better without beer.