You haven't said if you've ever camped on any level before which kind of puts me betwixt and between as to how to advice you. I know you said you are between a popup and hotel staying but as others have mentioned you have another option or 2: tenting or tenting and hotel staying combined.
No idea what kind of Nissan Altima you have or it's interior dimensions- sedan/coupe or hatchback? Got a hatchback w/ 60/40 seats? Maybe place a memory pad in the back and you and your dog will have a comfy sleep space. Just us a thought.
I can't think of many low weight PUPs with bthrm and kit for 2K or less so close to the summer time when campers of any sort are at a premium. .
