The latest Lithium-Ion powered jump starters for your dead battery are getting less expensive all the time.  They are very compact, ranging from only 3”-4” wide by 6”-8” long.  They take up far less space than a set of jumper cables.  The last one I bought on Amazon for under $80 was rated at 6000A and 12,800 mAh: plenty to turn over the bigger engines. They feature mistake-proof connections to prevent damage or injury.  You can also use them to temporarily supply power to your modern vehicles if you need to swap out the main battery - thus saving all your onboard computer and entertainment settings.  The vehicle electrical system only draws what it needs.

Which to buy? There are many brands and sources.  My advice?  Shop around.  Buy the most powerful you can find with what you are willing to spend.  Note: it is a good idea to check the battery status every month or so to make sure it is fully charged - before you need it - kinda like that spare tire.