Sure, check out the deathbrewer's stovetop method. You can do this small batch BIAB all grain method on a stove top or a propane burner.
If you can only boil 2.5-3 gallons, then you can only mash about 6lbs of grain MAX, which will make about a 3.5 gallon batch. You'd just mash in about 2 gallons of water, top off to as much as you can before the boil, then top off again to your expect OG after cooldown.
If you have a second pot, even a SS kitchen pot of about 2-3 gallons, you could do a dunk sparge BIAB, and easily make 5 gallon batches with the same method. Read through this and you'll know more of what I'm talking about