If the rest of the time I don't, my remaining time 6 months to 7 months from now on, let's do something fun together, just between us, that two people (I mean everything that is fun, sharing activities between our two people.)
If I had not much time left, my time remaining six months to seven months from now, let's do something fun together, just the two of us. (I mean everything, fun, activities, shared between the two of us).
If I don't have much time left, at the time of the rest of my 6 months to 7 month. Now, let's do something fun together, just the two of us. (I mean everything fun, the activities between the two).