In his case, the Doctor doubted either of them would still be here by 2034. Given advancements in technology and the unavoidable discord that would rise among the refugees, the Tesseract would likely be shuffled around and studied--hopefully properly--and send them all back. Or perhaps he would ultimately find a way to travel in the TARDIS again.
One way or another, he had little confidence in the longevity of their present statuses. The universe never did him any favors, and this one was bound to run out of kindness. They were terrible thoughts and he knew it, which made it difficult for him to nod along with the usual smile to her interest in life outside of Earth.
"Yes. Be a shame to let it go to waste," he agreed somewhat distantly, though didn't intend to appear that way. His mind was wandering again, so much so that he was silent until she prodded him for a proper answer to her question.
He avoided talking about the things that bothered him as a rule. Lately, he'd been attempting to improve on that so as not to lose their connection. Noting he'd failed in that regard again, the Doctor suddenly stood, hands in his pockets, and trotted over to the console where K-9 tinkered away at the lower panels.
While it looked as though he was outright ignoring her, the Doctor's eyes suddenly darted her way. "You've deduced an answer to that yourself, Rose, otherwise you wouldn't be asking it again. So. That leaves me with an answer I'm rather un-fond of giving: I don't know."
And just like that, he was snapping his fingers to shut the doors of the TARDIS and setting it into motion. He had to distract the both of them from addressing what he'd said further, that was his instinct.
"No wasting the sights, no, we'll have the best seat on the planet. If we're lucky, and we will be, we'll have a clear view of the Perseids meteor shower just before the moon's completely full. What do you think?" He was deliberately changing the subject and he knew it, but the very daft side of him hoped she'd go along with it.